Consider this a silver lining in Trump’s June meltdown for Republican border hawks. When last we all heard from Rubio, he was still resisting pressure from Senate colleagues to change his mind and run again in November as the GOP’s best, and possibly only, chance to hold that seat. But he was softening: He hinted to Hugh Hewitt that the terror attack in Orlando had forced him to think harder about his duty to serve the public in momentous times. The risk is that if he runs and loses another statewide race just eight months after being crushed by Trump in the Florida presidential primary, he’ll reek of loserdom. He’ll probably still cobble together a campaign and run for president again in 2020, but instead of a one-term senator who underperformed expectations, he’ll do so as a one-term senator who underperformed expectations twice. Who wants to sign on with a guy like that? Knowing that, and knowing that he’s potentially a formidable national candidate, Democrats will go all out to beat him this November — if he runs.

So if you’re Rubio and you’re trying to decide whether to chance it or ease into the private sector to make bank for a few years while plotting your comeback, the calculus is straightforward. The more competitive Trump seems to be with Hillary, the better you feel about your chances of winning reelection. The less competitive Trump looks, the more likely it is that he’ll drag you down too in your Senate race, which will all but end your presidential hopes. Rubio has nine days to decide (and maybe less than that, in order to be fair to Republicans who are already running in the primary). Given the trend in Trump’s polling lately, which scenario seems more likely for the fall? That Trump will run strongly enough to keep Senate Republicans competitive or that he’ll be an albatross around the necks of the entire party?

“Running for Senate in the age of Trump just sucks. And he knows that,” a Rubio ally said. “He’s already exasperated having to answer for Trump’s craziness. Now, every day will be like, ‘Donald Trump called Elizabeth Warren Pocahantas, do you agree?’ That’s not the kind of campaign he wants to run. But I’d be lying if I said I knew what he’ll do.”

The ally said Rubio is far more focused on a future White House bid. The first-term senator had planned to spend more time with his wife and four kids, get a high-paying job in the private sector and run “as the Washington outsider that he really is,” this person said.

Marco Rubio, Washington outsider? He’ll still be an outsider in 2020 if he runs again this year and loses, I suppose. He’ll just be an outsider who’s given everyone zero reason to believe he can win the presidency.

Democrats know that beating Rubio in the fall is a golden opportunity to kill a major presidential threat at relatively little expense, so they’re vowing to go all-in to beat him. That’s another major risk to him and the GOP if Trump ends up trailing badly for most of the campaign. The less Democrats need to spend to win the White House, the more they can spend to blow up Rubio and other Senate Republicans. But especially Rubio:

“Democrats are going to really go after him,” said one high-ranking Democratic source who asked not to be named discussing internal strategy. “Because if he loses this time, he’s gone for president in 2020.”…

[T]he DSCC and other Democratic outside groups, including American Bridge and the Senate Majority PAC, are preparing to spend tens of millions in the expensive state against Rubio, and officials say the attacks against the senator in the perennial swing state will be relentless.

The Democratic National Committee, which dug heavily into Rubio’s record in the presidential campaign, has already been in contact with the DSCC to share opposition research, according to a source familiar with the matter.

John Morgan, an attorney and major Florida Democratic donor, said that Rubio will be “done forever” if he loses a bid for a second term. To make that happen, he said, donors would pour big bucks behind Rep. Patrick Murphy, the favorite of the Democratic establishment, who is facing progressive firebrand Rep. Alan Grayson in the August primary.

There’s an obvious counterexample to the idea that Rubio’s done nationally if he runs this year and loses. Didn’t that happen to Richard Nixon? He lost the presidential election in 1960, then came back to run for governor of California in 1962 and lost that too. That prompted the famous line about not having Nixon to kick around anymore, followed by a six-year retirement, followed by … a presidential win in 1968. If Tricky Dick could do it, why not Tricky Marco? One obvious reason, I think, is that Nixon was a much higher profile figure than Rubio. He was a congressman turned senator turned two-term VP under Eisenhower, remember. He won the nomination in 1960, then lost a nailbiter to Kennedy. There was every reason to think he could win the primary and the national race in 1968. Rubio, having lost his crucial home swing-state twice and having famously lacked a real base in the presidential primaries, would face deeper doubts. He’ll also face likely competition in 2020 for the “diverse new face of the GOP” role in the primaries from Nikki Haley, who won her (deep red) state twice. If you’re Rubio, you’re better off being able to say that you chose temporary retirement from public service four years from now than that your own constituents forced it upon you, but you’re probably best off staying in the Senate and keeping your face out in front of the public in major debates. What’s an ambitious young pol to do when the guy at the top of the ballot looks like he’ll be an anchor?

Update: Carlos Lopez-Cantera is one of the Republicans currently running for Senate in Florida. He and Rubio have been friends for years; Rubio raised money for him and has said he won’t run again partly because he doesn’t want to muscle his pal out of the race.

But what if Lopez-Cantera nobly stepped aside? Here we go:

“You should reconsider running for your seat,” Lopez-Cantera told Rubio as they sat in the senator’s pickup truck about an hour before sunset, after witnessing the aftermath of the deadliest mass shooting in U.S. history…

“This is bigger than me. And this isn’t about me. And it’s not about you. It’s about our country and this election,” Lopez-Cantera said to Rubio, recounting the conversation for POLITICO. “It’s deeply consequential … In the current field, I’m the best candidate in the general election. But I’m not looking at this through rose-colored glasses.”

Rubio’s got the green light. What now?

Update: Rubio confirmed the conversation with Lopez-Cantera at a presser today and said he’ll spend the next week thinking things over.