Election forecaster Nate Silver says next week's midterms could mark the "end of the Trump era," as high gasoline prices and opposition to the Iran war add to President Donald Trump's political troubles.

"If the election goes roughly as the polls say it will go, then in some ways it would mark the end of the Trump era, I think," Silver said in an interview with Ezra Klein published Tuesday.

Trump would remain president for two more years, but Silver said a poor Republican showing could leave him a "super lame duck," comparing the potential aftermath to George W. Bush following the 2006 midterms.

Democrats need a net gain of four seats to take control of the Senate. Silver's election model launched in August giving them a 57.3% chance of taking the chamber, and his latest forecast puts them at approximately 76%.

That's roughly 10 percentage points above the 66% probability assigned by traders on Polymarket, where more than $9.4 million has traded on Senate control.

Iran War and Gas Prices Weigh on Republicans

Klein suggested Democrats might not be Senate favorites if Trump hadn't gone to war with Iran, driving up gasoline prices.

Silver said Trump's declining approval rating was "quite correlated" with gas prices, alongside broader economic anxiety.

Regular gasoline averaged $4.27 per gallon Tuesday, compared with $3.05 a year earlier, according to AAA. Silver Bulletin's polling average shows 55% of Americans oppose the war, against 36% who support it.

Silver estimated that the national political environment has shifted roughly 11 percentage points toward Democrats compared with the 2024 presidential election, exceeding the historical midterm average of 7.5 points against the president's party.

That has brought states Trump won by double digits, including Texas and Ohio, into contention.

"The fundamental conditions feel terrible for Republicans," Silver said, also citing strong Democratic candidates and controversies surrounding the administration.

Silver Flags an AI Backlash

Silver identified a potential "AI backlash" as a major election-night storyline, suggesting Republicans could underperform in areas where data centers are being built.

Morgan Stanley has warned AI investors that a Democratic sweep could weigh on infrastructure investment sentiment, potentially affecting companies such as Nvidia (NVDA).

Silver questioned whether Republican candidates could attract Trump's less-engaged supporters when the president himself isn't running.

"Those people are not gonna crawl over glass to vote for Roger Marshall or Ken Paxton, I don't think," he said.

Still, Silver warned that a three- or four-point polling error across several states could erase narrow Democratic leads.