Overconfident after his string of victories in the G.O.P. primary race, where he won the most votes ever cast for a Republican nominee, Donald Trump happily skipped into the general election predicting that he would trounce Hillary Clinton in several key swing states. Republican National Committee chief Reince Priebus and Trump campaign chairman Paul Manafort echoed his boasts, with Manafort predicting that nine states won by Barack Obama in 2012, including Michigan and Pennsylvania, are now “in play.” Trump himself recently claimed, confoundingly, that he is “leading [New Hampshire Republican senator Kelly Ayotte] in the polls” and “doing very well in New Hampshire.” A series of new polls released Thursday, however, tell a different story.

A slew of state polls released over the past week, taken in the wake of Clinton’s well-received Democratic National Convention and Trump’s series of self-destructive spat with two parents whose son died fighting in Iraq, show the billionaire developer trailing Clinton by several points, and by double digits in some cases. All of the polls, notably, were taken in states where Trump stomped his Republican opponents by double-digit margins just months ago, underscoring the challenge he faces in translating his primary season victories into general-election success.

In Pennsylvania, where Trump won more than twice as many votes as Ted Cruz, Clinton now leads Trump by an average of 8 points, with the latest poll showing an 11-point lead. A survey of voters in Michigan, which Trump won by double-digits in March, puts Clinton ahead by 9. In Florida, where Trump steamrolled the state’s own senator Marco Rubio, Clinton is currently posting a narrow lead of 2.7 points, a number that may increase if more Hispanic voters turn out for the general election. And in New Hampshire, where Trump received his first primary victory, walloping runner-up John Kasich by nearly 20 points, the nominee now trails Clinton by a massive 17-point deficit.

The stark contrast between Trump’s primary performance and his current polling is not surprising, given the vast differences between the primary and general-election electorate. While Trump received more than 13 million out of about 30 million votes in the G.O.P. primary, about 135 million people voted in the November 2012 presidential election. That’s a far larger—and much more diverse—pool of voters Trump needs to win over if he’s to have a chance at the White House.

As always, the latest data comes with caveats. There are still 97 days before the election, and while it seems inevitable that Trump will continue to alienate potential supporters, Clinton remains vulnerable to more hacking attacks like the one behind a recent Wikileaks document dump that was apparently timed to weaken her position. Trump has also stepped up his fundraising efforts over the past month, allowing him to build a war chest that could help him catch up to Clinton—if he ever starts advertising. And polls—as this election and past elections have proved—are not necessarily predictive of what will happen on Election Day, especially with three months to go.