And now there are three: U.S. Sen. Marco Rubio, R-Fla., who announced his candidacy for president Monday, is the third pro-school-choice, common-core-skeptical Republican senator to throw his hat in the ring. (The other two, for those keeping score at home? Sens. Rand Paul and Ted Cruz.) Rubio, however, also has a smattering of bipartisan efforts on education under his belt. More on that below.

While both Paul and Cruz have completely and totally shunned the Common Core State Standards, Rubio has been comparatively low-key in his criticism.

Still, it was considered a big deal when, back in 2013, Rubio told the Tampa Bay Times that, “This effort to coerce states into adhering to national curriculum standards is not the best way to help our children attain the best education.”

Why was that news so huge? It put Rubio at odds with one of his political allies and mentors, common core supporter and former Florida Gov. Jeb Bush, who is, incidentally, also (almost definitely) running for president.

Rubio has been a lot more vocal when it comes to another education priority: expanding school choice. He’s proposed federal tax credits for private school. And he’s supported the efforts of Sen. Mark Kirk, R-Ill., to bolster charter schools.

On accountability, Rubio is also a co-sponsor of the “A-plus” Act, which would allow states to essentially opt out of any requirements in the federal law. (The Heritage Foundation, which helped stall the current House rewrite of the Elementary and Secondary Education Act, is a big supporter of the “A-plus” Act.)

And, when he started mulling a run for president, Rubio joined Paul and Cruz in calling for dismantling the U.S. Department of Education, which would be really hard to do in practice.

In the Senate, Rubio has been involved in a few pieces of bipartisan legislation, which includes teaming up with Sen. Chris Coons, D-Del., on a bill to create “American Dream” accounts that help low-income students prepare for college, and with Sen. Bob Casey, D-Pa., on promoting computer science education.

And on the higher education front, Rubio collaborated with Sen. Ron Wyden, D-Ore., on legislation to bring more transparency to the process of picking a college.

So, on education in the campaign, will Rubio sound like mostly like Paul and Cruz? Will he emphasize his hint of a centrist side? Or will he pretty much just stick to the edu-policy nearly all Republicans love: school choice?

Sen. Marco Rubio, R-Fla., waves as he walks from the stage after speaking during the Conservative Political Action Conference in National Harbor, Md., on Feb. 27.--Carolyn Kaster)/AP-File