After Tuesday’s primaries, President Joe Biden and former President Donald Trump have mathematically clinched their parties’ nominations. And now, it’s off to the races. Over the past week, Biden has made campaign stops in Pennsylvania, Georgia, New Hampshire, Michigan and Wisconsin. Trump was also in Georgia last weekend and he’ll be in Ohio on Saturday. These kinds of campaign stops are a cornerstone of presidential campaigns and we can expect a lot more of them between now and November. There’s only one problem: According to political scientist Chris Devine, they don’t actually work. At least, not all that well and not in the ways you’d expect. In this installment of the 538 Politics podcast, Devine talks about his recently published book called, “I’m Here to Ask for Your Vote: How Presidential Campaign Visits Influence Voters."