Early polls don't always foretell the fate of a first-term president. Does anything?

Presidential approval numbers, like swimmers, cause alarm if they stay underwater too long.

President Biden's approval numbers in the Gallup Poll have been "underwater" – meaning they have been below 50% — since August of 2021, his seventh month in office.

His Gallup has fallen as low as 37% at several points in the past 18 months, including his readings for October and November 2023. Biden's approval was 40% in the latest NPR/PBS News Hour/Marist poll in December. The average of national polls calculated by 538.com had Biden below 40% for most of January.

That's not just underwater, it's deep underwater.

Since modern polling began, the first-term presidents who were unable to reach 50% approval at any point within a year of their next Election Day have not won a new term.

Examples of those who were denied reelection include one-term Presidents Gerald Ford (1976), Jimmy Carter (1980), George H.W. Bush (1992) and Donald Trump (2020).

By that same token, incumbents who had better than 50% approval with a year to go to reelection have usually won – and often won easily. Think of Dwight Eisenhower in 1956, Richard Nixon in 1972, Ronald Reagan in 1984, Bill Clinton in 1996 and George W. Bush in 2004.

So 50% in the polls has become more than just another reference point. Yet there's not really any predictive magic in that number or in polls in general.

Since World War II, four presidents have managed to win reelection after dipping below 50% approval in the Gallup at least once with a year or less to go to their moment of reelection truth: Harry Truman, Bill Clinton, George W. Bush and Barack Obama.

Conversely, some incumbents who had at least briefly been above 50% in their final year were soundly beaten in November —