As Joe Biden prepares to take the mantle of presumptive Democratic nominee, he’s facing a new round of questions about his mental acuity at age 77.

The questions have come from both the former vice president’s left and right. Since his decisive wins on Super Tuesday, President Trump has suggested Biden isn’t all there mentally. Over Twitter and in brief interviews with reporters, Trump has jabbed at Biden, saying he’s “lost his fastball,” and is not “playing with a full deck.” Last week, Trump said Biden would “destroy” entitlement programs without “even know[ing] he’s doing it.”