If you aren’t seriously contemplating the biggest black swan event in American electoral history, you aren’t paying attention.

Fifteen months ago, Donald Trump was a reality-TV star with a spotty business record and a weird penchant for proclaiming he was on the verge of running for president. Now, he’s perhaps a few big breaks and a couple of sterling debate performances away from being elected 45th president of the United States.

Trump has no experience in elected office, and unlike past nonpoliticians elected president, hasn’t won a major war. He barely has a national campaign. He perhaps knows less about public affairs than the average congressman. He has repeatedly advertised his thin-skinned vindictiveness and is trampling on basic political norms, like the convention of candidates releasing their tax returns.

No major political party has ever nominated anyone like this. If Trump were to prevail, it would make Barack Obama’s unlikely rise from unknown state senator to first African-American president of the United States in about four years look like a boringly conventional political trajectory.