(CNN) Since the day he was sworn in as President, whispers have circulated in Washington that Donald Trump won't run again in 2020.

The logic goes like this: Trump can't stomach losing, or even the prospect of losing. Given where he is -- and has been -- in national polls, losing is a very real possibility. Faced with such an unacceptable rejection, Trump will walk away -- proclaiming that his work as President is fully accomplished -- after a single term.

I've never, ever believed that theory for a simple reason: Trump has spent his entire life clamoring for the limelight and the recognition -- grudging or otherwise -- that being president affords him. Why would he EVER walk away from that?

Now, after the events of last Friday, Trump has even more incentive to stay in office: Because a sitting president can't be indicted.

Here's what we learned on Friday:

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