According to the latest RealClearPolitics average, Biden is sitting at 49.3 percent in national surveys and has a 6.2 percentage point lead over President Donald Trump. That’s significantly higher than Clinton’s 44.9 percent mark this time four years ago, which was good for only a 1 point lead.

It’s the same story in many of the battleground states: Biden is at or within 2 points of majority support in enough states to lock down an Electoral College victory, compared with Clinton’s low- to mid-40s scores in mid-September 2016 in the same states, some of which she would end up losing as late-deciding voters went decisively for Trump.

“One of the worries that kept me up at night in ’16 was we just always felt like there was a bigger number of undecideds. And if they broke predominantly in a direction, then the whole thing could change,” said Steve Schale, a Florida-based Democratic strategist and the executive director of a pro-Biden super PAC. “I don’t think there was a single poll in Florida that had [Clinton] over 48 percent. I think that was the case in a lot of places.”

It’s a fundamental difference in Democrats’ standing compared to this time four years ago. While Biden has not locked up the election, the path to victory that Trump took in 2016 is currently blocked.

Trump is mired in the low- to mid-40s — roughly where he was four years ago. But this time, Trump is the incumbent president. And with fewer undecideds or voters poised to select third-party candidates, Trump is running out of time to improve his poll numbers and close the gap.

“As the incumbent with a tough approval rating, he needs to kick it up. And obviously he’s trying to do that by squeezing a few more votes out of his base, at the risk of even annoying other [voters],” said Lee Miringoff, director of the Marist College Institute of Public Opinion, which last week found Biden leading Trump in Pennsylvania and tied with him at Florida. “So the Biden number is interesting — and obviously, if you get 50 [percent], that’s the home run.”

In Florida, the latest RealClearPolitics average has Biden ahead by nearly 2 percentage points, 48.7 percent to 47.1 percent. While Biden’s margin is not meaningfully different from Clinton’s 1-point deficit this time four years ago, both Clinton (45.2 percent) and Trump (46.2 percent) were in the mid-40s, thanks to a larger pool of undecided voters.

In most of the 13 swing states identified by POLITICO — those rated as toss-ups or just leaning toward one party in our Election Forecast — Biden is not only outperforming Clinton in terms of the margin between him and Trump, his average vote share is also greater than Clinton’s was at this point four years ago.

Biden leads in 10 of the 13 states, according to RealClearPolitics averages, trailing Trump only in Georgia, Iowa and Texas. In Sept. 2016, Clinton also trailed in Arizona, Florida and Ohio.

In addition to nearing 49 percent in Florida, Biden is at 49.2 percent in Arizona, 47.8 percent in Michigan, 51.6 percent in Minnesota, 48 percent in New Hampshire, 49 percent in Pennsylvania and just over 50 percent in Wisconsin.

Victories in those states, where Biden's lead over Trump is at least 4 points, would clinch the presidency for the former vice president even if Trump won the other swing states. In fact, if Biden won Arizona, Michigan, Minnesota, New Hampshire, Pennsylvania and Wisconsin, he could afford to cede Florida, Nevada, North Carolina and Ohio — each of which he leads right now — and still become the next president.

Trump’s vote share in some states, like Florida, is also a little closer to 50 percent than four years ago. But almost across the board, Biden is outperforming Clinton by greater margins than Trump is outrunning his own 2016 performance.

“We don’t have a dominant third-party candidate who is going to take a big chunk of those voters who are like, ‘I hate both of them,’” said Republican pollster Jon McHenry. “So they should be a little bit closer [to 50 percent].”

That means that Trump can’t just rely on the kind of late surge he got four years ago to gobble up undecided or third-party voters. He needs to persuade at least some voters who say they prefer Biden to switch in the closing weeks of the race, a task made more challenging by Trump’s position as the sitting president.

“It’s always hard to convince someone who’s made a decision to do something not to do it,” said Schale, the longtime Biden ally. “And I think the other challenge Trump has is he wasn’t an incumbent [in 2016]. There wasn’t a record, and — historically — job approval matters in these things. He’s in the mid-40s in a lot of these states.”

As an incumbent with low approval ratings, Trump has fewer remaining opportunities lefto make the kinds of gains he needs, particularly with voting already underway in a handful of states — and set to begin soon in many others.

“Even if you were talking about a race being 48 [percent] Trump, 46 Biden — you wouldn’t feel bad about Biden’s chances in that scenario because he’s the challenger, and you want the incumbent to be at 50 or above. Especially if there’s not a significant third-party vote this time,” said McHenry. “So, if you’re looking at it from that perspective, really, Trump is running against 50. And whether he’s within 2 or 3 of Biden, you would want to see him making some gains sooner rather than later.

“I still think that this race can wind up turning on the first debate,” he added. “I’d be hesitant to make any bold predictions about the presidential race until we see what happens there.”