Voters do not need to play the role of armchair psychiatrist to see that Biden has lost a step. Despite all the attempts in the mainstream media to recast Biden’s troubles speaking as a lifelong battle with a stutter, it is plain to anyone with eyes and ears that the president who now struggles to make it through a speech is not nearly as sharp as the vice president who debated Paul Ryan in 2012.

It’s far from clear that the issue of age will sink Biden if he runs again in 2024, but it is clear that Republican primary voters could do a lot to help protect Biden from age-related attacks if they nominated Donald Trump for a third time. Trump’s worst mental deficiencies are his erratic personality and his conspiratorial mindset, but he’s also very old: If he ran and won in 2024, he’d be 82 by the time his term ended in January 2029.