Since we're now only five weeks away from the midterm congressional elections, it's time once again to take a quick look at all the competitive Senate races. The map has been expanding, as more and more states that used to be considered solidly in the Republican column have moved to being close races. This is obviously good news for Democrats, since it provides them with multiple ways to win back control of the chamber.

Democrats need a net gain of four seats to reclaim the Senate. They are playing defense in four states -- states that have been in Democratic hands up until now. They are playing offense in ten states now (although a few of them admittedly have to be considered the longest of longshots).

Without further ado, let's run these down, one by one.

States Democrats are defending

This is a rather short list. Republicans can really only be considered contenders in four states that Democrats now hold. None of them is looking like a big blowout for the GOP, either. Democrats could very well hold all four of them.

Georgia

Out of all the states Democrats are defending where Republicans thought they had a chance, Georgia has surprisingly stayed pretty solid for the Democrats. Senator Jon Ossoff is running a good campaign against a Republican who hasn't caught fire at all. Ossoff is regularly polling over 50 percent, and some polls put him up by 10 percent. It's gotten so bad for the GOP that they're thinking of just abandoning the state and spending their money elsewhere.

New Hampshire

New Hampshire has an open Senate seat due to the retirement of Senator Jeanne Shaheen. While most people expected New Hampshire to stay in Democratic hands, Republicans nominated a dynastic candidate, John Sununu. He has previously served in the Senate for New Hampshire, and his brother and father were both governors of New Hampshire as well.

Chris Pappas, the Democrat in the race, has gotten some pretty good polls this month, though. Except for one outlier that shows a tie, Pappas is up in the other six polls by anywhere from 5 to 11 points. His chances have to be seen as pretty good to win the state, at this point.

Minnesota

This one is kind of a surprise, since up until now it had been considered fairly safe for Democrats. But while the polls showed Lieutenant Governor Peggy Flanagan with a healthy lead for a while, the numbers have gotten closer over the past month. The Republican, Michele Tafoya, is known for her role as sideline reporter on Sunday Night Football. The race is an open one, since Democratic Senator Tina Smith is retiring.

In the four polls released this month, Flanagan had a lead of 2 points, 4 points, and 1 point -- but the most-recent poll showed a tie, at only 42 percent. So the Republicans are getting more optimistic about their chances here.

Michigan

Michigan is going to be the real nail-biter for Democrats in November. This is an open seat, since Senator Gary Peters is retiring. The nomination of Dr. Abdul El-Sayed on the Democratic side has introduced a lot of uncertainty into the race, since he is very progressive and not a big fan of the Israeli government (to say the least). He is seen by Republicans as some sort of dangerous radical (if not worse) and the campaign against him has been more than a little tinged with racism and Islamophobia. But he is an excellent campaigner and seems to have healed the wounds within the Democratic Party from a rather brutal primary campaign (against a moderate backed by the establishment wing of the party).

El-Sayed is leading in the recent polling, but not by a whole lot. His average poll lead is only 3.3 percent, according to RealClearPolitics. This race truly could go either way, but if El-Sayed pulls out a victory it could be an early sign that the big blue wave truly has materialized.

States Republicans are defending

This list has been growing, all year long. At first it only had a handful of states in it, but we're now up to a whopping ten states that the GOP now holds but could flip to the Democrats -- most of them states where Donald Trump won by fairly large margins.

This list is roughly in order of Democrats' chances of picking up these states, from highest to lowest.

North Carolina

As in Georgia, Republicans are contemplating just ceding North Carolina to the Democrats by pulling all their spending out and using it in states where it might actually make a difference. The seat is an open one, due to the retirement of Republican Senator Thom Tillis (whom Trump essentially forced out). The Democratic candidate, Roy Cooper, is a former governor of the state who was well-loved while in office. His opponent, Michael Whatley, is little-known and from all accounts has been running a terrible campaign. Cooper has taken a commanding lead in the polling (8.6 percent up, on average) and has led every single poll so far. Out of all the states Democrats are hoping to flip, North Carolina is the one that looks like a done deal, at this point.

Ohio

Ohio is one state where the results might be closer than the polls indicate. It could wind up being the most expensive Senate race ever, as both sides have sunk an enormous amount of money into the race. Democrat Sherrod Brown, who used to be a senator from Ohio, is running to get his old job back. Senator Jon Husted is running to keep his current job (which he has never been elected to -- he was appointed to replace JD Vance).

One of the big factors in this race is data centers, and artificial intelligence companies have poured a ton of money into anti-Brown ads. But one wonders if the airwaves in Ohio are so saturated by political ads at this point that it might not have much effect (people eventually either tune it all out get extremely annoyed by the omnipresence of such ads).

Brown has always been an economic populist fighting for the little guy, even before Bernie Sanders made it cool. He's a big Union guy and has gotten a lot of support from labor organizations in the state. He has led every poll that has been released this month, but mostly in the low single digits (his average lead is only 3.7 points right now). So this one could be very close indeed, on election night.

Alaska

Mary Peltola has won statewide in Alaska before, serving as the state's only member of the House of Representatives. She is running for Senate this time around to unseat Senator Dan Sullivan. Local issues (such as fishing) feature prominently in her campaign, and she is trying to sink Sullivan for his support for Trump's agenda -- especially his war of choice with Iran. In some remote places, gasoline is selling for over 10 dollars a gallon in Alaska, which is why the war's costs are such a big deal there.

Peltola has a decent shot at winning, but polling in Alaska is notoriously hard to do with any accuracy. Peltola has been leading in most polls, but not all of them (and never higher than six points up). As it always is, Alaska is anyone's guess -- it really could go either way in November. But Peltola seems to be running a very good campaign.

Maine

Maine is another state that has to be seen as completely up for grabs. This race has been a real whirlwind, with a progressive candidate beating out the pick of the Democratic Party establishment, and then crashing and burning. Troy Jackson was selected as the replacement pick by the Maine Democratic Party (since it happened after the primaries were over). He isn't as charismatic, but he does have solid working-class roots and is seen as authentic by Maine voters. But Senator Susan Collins has beaten the odds before, and she could very well do so again. Collins has a lot of seniority in the Senate, which allows her to direct lots of federal money to the state. But her vote to confirm Justice Brett "Fratboy" Kavanaugh may wind up being her downfall (especially since she refuses to say she is sorry for her vote on him).

This one is a complete tossup. The polls are very close, and both candidates have recently led (in different polls). We'll all be watching Maine election results anxiously in November, that about the only thing that can be said with any certainty.

Iowa

This was a surprise, to see Iowa even competitive. In fact, the rest of this list falls into that category as well.

Iowa's Senate race is an open one, as Republican Senator Joni Ernst is retiring. The Republican running to replace her currently serves in the House. Representative Ashley Hinson has voted multiple times to support Trump's war of choice in Iran, which is now causing her some political problems. In fact, she recently tried to convince the voters that she is pushing for an end to the war. The only problem with this stance is that she keeps on voting to continue the war every time the Democrats force a resolution to end it through Congress. Both the war (and the sky-high prices of diesel fuel and fertilizer) and Trump's tariffs have hit Iowa farmers hard, so blind support for Trump isn't really what the electorate seems to be looking for right now.

However, Iowa is a very red state. Josh Turek, the Democratic candidate, has been much more competitive than anyone expected, and the polls are neck-and-neck (both candidates have led recent polls). If a blue wave does develop and the Democratic turnout is energetic and massive while the Republicans mostly stay home, then Iowa could indeed be flippable for Democrats. But it's probably going to be a close race.

Texas

Texas really shouldn't be competitive at all. It really should be solidly in the Republican column. If Texas Republicans had just nominated their sitting senator, John Cornyn, then they'd be on an easy glide path right now to holding his seat. Instead, they followed Trump's lead and booted Cornyn out in the primary, choosing scandal-plagued Ken Paxton instead.

James Talarico, the Democrat running, has been running a great campaign and has led every poll released this month. He has managed to heal the rift that a contentious primary left among Texas Democrats, while Paxton has been struggling to get all the state's Republicans behind him (Paxton's primary win was beyond brutal -- much more vicious than the Democratic contest for multiple reasons). Right now, Talarico seems to have the edge, but then again flipping Texas blue has long been the "impossible dream" for the national party (because all their hopefuls have always wound up just short of actually winning). This could be the year that changes -- but then we've said that in the past and it didn't happen. So anything could really happen in the Lone Star State in November.

Kansas

Kansas is another rural state where the high price of diesel and fertilizer (as well as Trump's tariffs) have disillusioned a lot of farmers who voted for him. Senator Roger Marshall is running for re-election, but he's got a real challenge on his hands from Adam Hamilton, who founded one of the largest churches in Kansas. That goes a long way in a state like Kansas, which is likely why this is (surprisingly) such a competitive race.

Polling is almost nonexistent in Kansas, but with the race being so close perhaps that will change in the coming weeks. The most recent poll put Hamilton up by two points, and national Republicans are getting very worried about the prospects of losing here. If Kansas does go blue, the Democratic blue wave is likely to hit tsunami proportions -- but that is not out of the realm of possibility, at this point.

Nebraska

Nebraska isn't really technically an opportunity for a Democratic pickup. The Democratic Party didn't run any Senate candidate here. This was intentional, to boost the chances of an Independent candidate, Dan Osborn. He ran for Senate two years ago and lost, but this just helped him build name recognition in the state. He's a very blue-collar guy (a Union leader) and he is running a "pox on both their houses" outsider race. Even if he wins (which has to be considered a longshot at this point), he says he will not caucus with either party. So Democrats won't exactly get a pickup -- they won't add to their own ranks in the Senate -- but they might just subtract one from the Republicans.

South Carolina

The remaining two states have to be seen as the longest of longshots, but it's the kind of year when Democrats are dreaming big, so I decided to include them for the sake of completeness.

After the sudden death of Senator Lindsey Graham this year, his sister Darlene Graham Nordone was named to replace him. But she has not exactly overwhelmed Republicans in her state with her competence, so she her standing is rather shaky in this otherwise very red state. Democrat Annie Andrews has been more competitive than expected, trailing Graham Nordone by only a couple of points in the polls. If Andrews pulls off a victory, it might just be the most stunning upset of them all this cycle. But the safe bet is the state will stay in Republican hands.

Florida

Florida is an even bigger longshot for Democrats than South Carolina. It also features a sitting senator who was appointed (and thus has never won a statewide election for the seat). Ashley Moody was appointed to replace Marco Rubio, when he left to join Trump's cabinet. She is being challenged by Democrat Angie Nixon.

Nixon is a democratic socialist and is a Black woman as well. If she pulled off an upset, she'd be the first Black senator from Florida ever. Her primary victory was a stunning upset, but she faces some serious headwinds in the general election contest in a very red state. The polling has been pretty heavily tilted towards Moody, although one recent poll did show the race as being tied. If Nixon does pull off this upset, then the blue wave will truly be of titanic proportions this year, that's a pretty safe bet.

Conclusion

A year ago, only cockeyed optimists had any hope that Democrats could actually win back the Senate. Now, it's considered a strong possibility. The House seems like a foregone conclusion at this point -- some analysts are even predicting Democrats will pick up as many as 20 or more seats, which would be a complete blowout.

The Senate map for Democrats keeps expanding, though. Republicans, from Donald Trump on down, are having to spend time and money on states nobody ever thought would even be in question. Trump is visiting Oklahoma and Alabama this week, which is just jaw-dropping when you think about it (although, to be fair, neither state seems to have a Senate race Democrats even have a chance in).

All Democrats have to do is pick up four seats overall. One (North Carolina) seems to already be in the bag for them. Others seem eminently possible as well. Barring any bombshell of an October surprise, the races all seem to be hardening. The voters have soured on the economy and have turned against Trump in a big way. So while there are no guarantees at all and things could easily go either way, Democrats are now in a position that was almost unimaginable last year. They have the wind at their backs and are competitive in states nobody thought they'd ever have a chance in.

We've got five weeks to go, but at this point I am at least cautiously optimistic that Democrats could indeed wind up in control of the Senate next year.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant