President Joe Biden and former President Donald Trump have both told aides and confidants that they’re more likely to run for the White House next cycle — and confident in their chances of winning — if the other runs, too. But as each camp gears up for a rematch of the bitterly contested 2020 contest, there remains a small hiccup: Neither is inclined to take the plunge first.

It’s a game of political chicken that — as described by more than a half dozen advisers to the two men — has largely frozen the field among Democrats and Republicans alike, raising questions about the future health of two parties being led by a pair of candidates who, by that Election Day, would have long ago celebrated their 75th birthdays.

“It’s a very unusual situation where there are people in both parties who would likely clear the field, and for the first time in modern history we might not have a very competitive primary on either side,” said Alex Conant, a Republican strategist who was a senior adviser on Sen. Marco Rubio’s presidential bid. “So it’s hard to think of what that would look like other than it being a brutally long election campaign.”