“She is indeed the front-runner,” Zogby told the Washington Examiner, adding the race is now a two-person contest between her and Biden. “There’s a definite and distinct rise in her polling numbers. She’s good out there, she’s drawing crowds. She clearly raised a lot of money.”

But there’s always the fear that she’s peaked too soon, Zogby explained, citing the Republican 2012 primary where “everybody led for at least a month,” before Mitt Romney emerged as the nominee.

“So far there isn’t any evidence of her fading, but it could be that she gets tiresome,” said Zogby, citing the rise of a little-known Democratic Vermont governor around this time in 2003. “It could be, as in the case of Howard Dean in 2004, that she leads all year and then right before the Iowa causes, ‘Pow,’ It remains to be seen. We’ve got a few more months ago.”

Biden on Wednesday tried to push back on the notion that he’s no longer the favorite for his party’s nomination.

“I haven’t seen any polling showing that nationally, on average, that anybody else is the front-runner,” Biden said at a union event in Columbus, Ohio.

While tentative about using the word “front-runner,” Charles Franklin, director of the Marquette Law School Poll, described Warren “as the one to watch,” especially now that she’s surpassed Vermont Sen. Bernie Sanders in the polls.

“In some polls she has caught Biden, though not in others. Biden has not moved down so much as oscillated between 26% and 30% since the first debate in June. But Warren has moved from 5% in March to close to 25% now, and done it with steady growth, not short-lived bounces,” Franklin told the Washington Examiner.

Franklin also warned that Warren’s front-runner mantle came with “the challenge of becoming the center of attention and criticism.”

David Axelrod, chief strategist for Barack Obama’s successful 2008 and 2012 presidential campaigns, said Warren has earned front-runner status by fending off multiple attacks from rivals on the debate stage Tuesday.

“.@ewarren status as front-runner has been certified by the amount of incoming she is getting tonight,” he tweeted.

Zac Petkanas, a Democratic strategist and former senior Hillary Clinton aide, praised Warren’s handling of the pressure.

“Warren isn’t letting anyone land a punch,” he wrote.

Larry Sabato, director of the University of Virginia’s Center for Politics, called Tuesday night “the @ewarren debate.”

“You might be happy or sad about it, but she’s the one who is setting the tone and she’s the reference point for most of the other candidates,” he added.

After an “outlier” Monmouth University poll in August found the contest was a three-way tie between Biden, Warren, and Sanders, Warren has slowly siphoned support from Biden and Sanders in a slew of state and nationwide polls.

Biden and Warren, in particular, have traded places atop of RealClearPolitics’ ranking based on polling averages. The senator first seized the lead earlier in October to have a 0.2 percentage point advantage over the former vice president. As of Wednesday, she now trails him by 6 percentage points.