Last week, Iran offered Donald Trump an offramp. Days later, Trump announced he was refusing to take it. The offer reportedly came after a meeting on the sidelines of the U.N. General Assembly, where the two sides talked for the first time in months. Iran essentially offered up virtually the same deal that was agreed to in the Memorandum Of Understanding earlier this year, except with a one-week timeline. Trump turned it down.

Trump called the deal unacceptable and said he hoped that talks between the two sides would continue. This is more than a little strange, seeing as how he had indeed accepted basically the same deal earlier this summer. Perhaps he has figured out by now that the M.O.U. deal was indeed heavily tilted towards Iran's demands, while addressing virtually none of America's priorities. It was a bad deal to begin with, in other words, which Trump may have belatedly figured out.

The deal that was offered would have given Iran most of what they want, including unfreezing billions of dollars held by foreign banks, an end to the American military preventing shipping from reaching Iran, and an end to all the U.S. sanctions placed on Iran. Only after all of this had been achieved -- after Iran had gotten everything they wanted, in essence -- would Iran reopen the Strait of Hormuz. This was all supposed to take place in one week's time. Then at the end of that week (after Iran achieved all their goals by trading the reopening of a waterway that had been fully open before the war ever took place), the two sides would open negotiations into Iran's nuclear activities (which is now the sole U.S. goal, other than achieving the status quo ante bellum in the Strait).

Trump is right that what the Iranians are offering is heavily tilted towards their goals and openly dismissive of the U.S. goals. But that was true of the M.O.U. as well, which is why Iran is essentially offering up the same deal. "You agreed to it before," they can say in all honesty, "so why is it unacceptable now?"

If Trump had agreed to the new deal, he would have gotten one other thing as well -- a political lifeline, heading into the midterm elections. If Trump had agreed to the deal last week, then he could start bragging that: "The war is over!" and: We won!" Few other than his die-hard supporters would have believed that second part, but it wouldn't matter because the price of gasoline would have started to fall. That's what is really hurting Trump heading into the elections, and he knows it.

When the M.O.U. was agreed to earlier this year, gas prices did indeed start coming down in a very noticeable way. The world oil market breathed a temporary sigh of relief and prices turned downwards as a direct result. That would almost certainly be repeated if Trump suddenly announces a deal has been struck with Iran to cease hostilities and reopen the Strait.

With five weeks left before Election Day, there would have been enough time for consumers to actually see some relief at the gas pump. Trump could sell the idea that things are getting better and this would have provided a political boost for all his fellow Republicans. The fact that the deal was a particularly bad one would have mostly been obscured by falling gas prices. The American people would have been thankful for some economic relief and wouldn't particularly care how it had come about.

How much this would have helped Republicans is an open question, of course. Voters tend to form their views of how the economy is doing over the summer before an election, and those views tend to get baked into the cake by summer's end. Even radical economic shifts very late in the campaign cycle sometimes don't change many minds, to put this another way. But even if it had only a limited effect, the price of gas coming down from just under $4.50 a gallon to perhaps just under $4.00 a gallon by Election Day certainly would have helped Republicans to some degree or another.

The truly brutal thing for Trump and his fellow Republicans is the sky-high price of diesel fuel. The political media haven't really adequately highlighted this crisis, perhaps because unless you own a car or truck powered by diesel you don't really notice the price of it. And using the word "crisis" is not an overstatement, especially during harvest time. Diesel just went from a starting point of setting a new all-time record high ($5.82 per gallon) to skyrocketing up another 70 cents within two weeks' time, to set a new all-time high of $6.52 (according to AAA). The American economy as a whole hasn't felt the ripple effects of this pain yet, but farmers who need to burn hundreds of gallons of diesel a day to get the crops in are already feeling it.

This is a big reason why the political map has expanded so much for Democrats. Democrats are cautiously optimistic about their chances to win Senate seats in places where they normally wouldn't even have a chance -- states like Iowa, Kansas, and Nebraska. If the price of gasoline and diesel came down in a big way over the last month of the election, Republicans would likely rebound in such rural states (again, to some degree or another, but in a close election it doesn't take much).

But Trump refused to take the offramp offered to him. Of course, a deal could be announced at any time -- if negotiations are truly taking place in earnest, then an agreement could be reached and suddenly unveiled at any point. But the clock is ticking. The closer we get to the election, the smaller the political impact of any deal is going to be.

Iran was smart to repackage the M.O.U. and present it to Trump right now. They know that Trump and the Republicans must be desperate to have some sort of good news to offer up to the voters before the election. Trump seemed awfully dismissive of the offer, but he can change his mind in an instant at any time. The temptation to personally interject his own October surprise into the midterm elections to help his fellow Republicans might be the deciding factor in the end.

But for now, Trump refused the offer of an offramp and just sped by it, steering his party down the same road he's been on for months.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant