If any of the four front-running candidates wins the GOP presidential nomination, the Republicans will break a longstanding pattern that’s lasted in their party for nearly 50 years. In 12 elections in a row, the GOP has nominated someone who has run for president before—or spent time in the White House. Gerald Ford and George W. Bush hadn’t run before they were nominated, but Ford was an incumbent president and Bush had considerable White House experience during his father’s presidency.

This time, only Mike Huckabee and Rick Santorum have run for president before, and Jeb Bush comes from a presidential family. But even though he never declared his candidacy before this year, Donald Trump has publicly flirted with a presidential run on four prior occasions. Perhaps that’s one of the unacknowledged advantages behind his surprising popularity: though he’s never made a previous race, he’s already so familiar in this role that it seems as if he has.