For Marco Rubio, what might have been -- and what could still be

Sources close to Rubio commonly cite two fundamental weaknesses to explain the presidential defeat: a lack of grassroots organization and a light footprint in the early nominating states. Those lessons have been absorbed, his allies say, and quickly addressed during his Senate run.

Rubio’s first priority after he changed his mind and decided to seek reelection was to build out an extensive volunteer network. It had been missing in 2010, not that it mattered: He won an off-year election against mediocre opponents on the strength of enthusiasm, momentum, and narrative. Today, Rubio has 19 statewide offices, 25 field organizers, and more than 500 grassroots team leaders — numbers that campaign officials say dwarf his infrastructure of six years ago.

The second lesson was that Rubio had relied too heavily on reaching voters via mass media rather than spending extensive time on the ground. This fueled whispers among opposing campaigns that Rubio was lazy, a perception that wasn’t helped by his patchy Senate attendance record. The correction in his Senate campaign, especially down the stretch, has been noticeable: Rubio has been hitting four or five counties each day, zig-zagging across the state in a nondescript SUV. (It’s a “fourth gear” he says he didn’t know he had before 2016.)

There’s one other lesson Rubio learned — and by the sound of it, a regret he carries — from the presidential race. “You know, I’m probably more involved in my campaign for Senate at the detail level. From our message to where our ads are going to be placed, I’m much more involved at a granular level of the day-to-day campaign than I was running for president,” Rubio says. “That was probably a mistake, not doing it earlier, and part of it was the nature of the race. . . . That’s probably one of the things I’ve learned where, you know, you don’t want to micromanage, but I think I have something I can contribute to that aspect of it. And I think it’s made this a better campaign.”

Whether Rubio can apply these lessons to a future presidential race might depend on Tuesday’s outcome in Florida.