Why is Rubio running?

[King]

Question here. At what point does Rubio have to submit his resignation now that he's announced for President?

I don't think he would resign unless he clinched the nomination. But he definitely will have to announce that he isn't running for reelection.

Like Obama, Kerry, Mcgovern, McCain and JFK did huh?  Only Dole fell for that nonsense

None of those people were up for re-election the year they were running for President. Rubio will definitely have to lameduck his seat if he won the nomination. I believe it's the law in most states including Florida.