He’s unpopular, combative, divisive and perpetually bogged down in controversy. But it’s still plausible that Donald Trump could win a second presidential election in 2020.

That’s the assessment of Greg Valliere, chief global strategist for Horizon Investments, who offered some political prognostications at the Yahoo Finance All-Markets Summit on October 25. “Who’s going to beat him for the [Republican] nomination?” Valliere said at the summit. “Kasich? He lost every primary except Ohio. I think [Trump’s] the nominee if [he] wants it. Then you have to say, ‘If the [Democratic] front-runner is Bernie Sanders, who’s 76, or Joe Biden, who will turn 75 next month, Trump has a chance.’ ”

That scenario relies on a few things—most notably, that Trump avoids charges in the sprawling investigation run by special counsel Robert Mueller. And he may. Mueller has now indicted Paul Manafort, Trump’s former campaign manager, on charges related to foreign business dealings prior to his dealings with Trump. But Trump is right (so far) that the charges against Manafort have nothing to do with the Trump campaign. Trump clearly picked some fishy characters to help run his campaign, but that doesn’t mean his campaign did anything wrong.

Trump’s prospects in 2020 also depend on whether he faces compelling new candidates in the Republican primaries or the general election. And it’s a pretty good bet some newcomers will give it a run. A handful of Republican senators may challenge Trump for the nomination, including Jeff Flake (Arizona), Ben Sasse (Nebraska) and Tom Cotton (Arkansas). Trump’s ambassador to the United Nations, Nikki Haley, could run, as could his vice president Mike Pence. Prior contenders such as Sen. Marco Rubio (Florida) and Sen. Rand Paul (Kentucky) could give it another whirl. Same with Mitt Romney, the 2012 Republican nominee, and his former running mate, Rep. Paul Ryan (Wisconsin).

Democrats know they need fresh blood, and senators such as Elizabeth Warren (Massachusetts), Cory Booker (New Jersey), Amy Klobuchar (Minnesota) and Kamala Harris (California) may be eager to provide it in 2020. Tim Kaine (Virginia), Hillary Clinton’s running mate in 2016, could seek the top spot on the 2020 ticket. Governors such as John Hickenlooper of Colorado and Andrew Cuomo of New York have shown interest in running. A business exec such as Disney CEO Bob Iger or Starbucks Chairman Howard Schultz could try to become the Trump of the Democratic party. The real question for each party isn’t whether newcomers will run—it’s whether they’ll get traction if the party machinery favors a stalwart such as Biden.