The real challenge for Rubio early on is that he is mostly now known for just one thing among Republican primary voters: trying to lead on an immigration compromise with Barack Obama, and failing. Even at his book signing in Iowa, that’s the issue most associated with him at the moment, and it’s impossible to put it behind him. A rational evaluator would look at this circumstance and realize the opportunity in waiting to run in a few years, when the idea of Obama’s amnesty is less toxic and immediate, when he’s had an opportunity to lead with success in the Senate on a number of issues, and when he won’t be going up against a very strong field of leaders with executive experience. No one else this cycle faces the challenge of Jeb Bush as directly as Rubio: Bush will not just lap the field in fundraising, he is more popular in Rubio’s own state, and among many of Rubio’s own donors. That’s a unique handicap indeed.

Rubio has said that if he runs for president, he won’t run for re-election to the Senate. If this is true, it makes the risk of running enormous – essentially, it means he’s rolling the dice on his entire political career. Ted Cruz has a safe seat and can entertain a run without risking it, but Rubio has a much more challenging future for running statewide. And the alternate Senate-based path for Rubio is an appealing one: he can run for re-election and could be well on his way to becoming the consensus floor leader in a few years. Rubio’s gifts are real: he’s a great communicator, doesn’t make the party look stupid, and is good at keeping people together. He’s tactically aggressive, but at his best training fire on the other side, not inside his coalition. He’s got much of the toolset one would want in a caucus leader, and the base that might condemn his immigration views would assuredly welcome him compared to the other potential candidates.