Ahead of 2024 Democratic presidential nominee Kamala Harris’ and her running mate, Minnesota Governor Tim Walz’s Philadelphia rally Tuesday, former President Donald Trump shared a social media post that is causing political experts to question his sanity. Senator JD Vance (R-OH) — Trump’s running mate — also appeared at a separate event in Philadelphia on Tuesday, in which the GOP lawmaker called the vice president a “disaster,” and the governor a “radical lefty.” The former president took to Truth Social ahead of Harris and Walz’s appearance, writing: What are the chances that Crooked Joe Bid…