Unfortunately for Democrats, they probably won’t have Speaker Nancy Pelosi to guide their efforts since she is likely to retire next year. And House Democrats could also lose other savvy legislators and party leaders if Majority Leader Steny H. Hoyer and Majority Whip James E. Clyburn, who like Pelosi are now in their 80s, decide to walk away.

If Republicans capture the House and/or the Senate next year, Biden can wave goodbye to the rest of his agenda. Indeed, if Republicans capture both chambers in a midterm partisan wave, they would be able to work together to pass legislation that puts Biden in an awkward position.

Over the slightly longer term, things get even worse for Democrats.

The Senate class up for election in 2024 represents a potential disaster for Democrats, with at least 10 Democratic-held seats in competitive states, including in Montana, Ohio and West Virginia.

Biden’s age — he’ll turn 82 shortly after Election Day 2024 — raises questions about his health and electability, and it’s far from clear what kind of nominee Vice President Kamala Harris would be as Biden’s successor.