The 2018 midterm elections will surely be a referendum on the sitting president, as midterms always are, but new polling shows that Donald Trump will play a particularly outsize role when voters head to the polls in November.

A higher share of voters say Trump will be a factor — either positive or negative — in their vote in 2018 than any previous president in any election dating back to 1982, according to new data from the Pew Research Center. Most of those, 34 percent, said their vote will be decidedly against President Trump.

(The Pew survey was conducted from June 5 to 12 and surveyed 1,608 registered voters. The margin of error for questions asked of all registered voters is 2.9 percentage points.)

The Trump antipathy is, unsurprisingly, driving Democratic voters to the polls. According to Pew, 61 percent of Democratic voters said their vote would be a vote against Trump. That is notably higher than the percentage of Republican voters who said their vote was a vote against Obama in 2010 (54 percent) and 2014 (51 percent) when the GOP made major gains in Congress, retaking the House and then the Senate.

This tracks with recent enthusiasm Democrats have seen in special elections around the country, showing a high level of turnout for relatively low-profile races — even in some deep-red districts.

The most recent midterm election to be defined to this degree by opposition to the president, according to Pew, is 2006. That year, during the height of the backlash to the Iraq War and after a failed GOP run at privatizing Social Security, 65 percent of Democratic voters said their vote would be against George W. Bush. The result was that Democrats won 31 seats in the House and retook control of the chamber.

If there is any hope for Republicans, it’s that their voters are still mostly united behind Trump, even as the president galvanizes his opposition. A majority of Republicans say they will be voting for Trump in 2018, a much higher share than said they were voting for Bush in 2006 and even outpacing the share of Democrats who said they would be voting for Obama in 2010 and 2014.

But the picture painted by the Pew data is that Trump is the subject of substantial backlash among opposition party voters, at or even exceeding the levels typically seen during elections when the party out of power made substantial electoral gains and seized control of at least one branch of Congress.

You see it also in the enthusiasm of Democratic voters: 55 percent of voters who support Democratic candidates said they were more excited than usual about voting in 2018, even higher than the enthusiasm seen in 2006 and matching the enthusiasm of Republicans in 2010 when they won 63 seats and a sizable majority in the House.

Trump won’t be the only factor in 2018, of course. Democrats are contending with gerrymandered districts in many House races, they have to defend 10 Senate seats in states that Trump won in 2016, and issues like health care and immigration will likely dominate the policy debate. The economy, as always, should play an important role.

But the president, as in all things, is making his presence felt. Judging by the Pew results, he’s going to be more of a drag on his party than Obama ever was.