Sen. Marco Rubio (R-Fla.) (Alex Wong/Getty Images)

Is Sen. Marco Rubio (R-Fla.) worried about where he stands with large elements of the Republican base? Since becoming the chief GOP advocate for immigration reform, he’s had to have a delicate touch, assuaging the concerns of anti-reform conservatives, presenting his proposal as a step away from “amnesty,” and building an argument for why the Republican Party needs immigration reform now, rather than later.

Over the last week, Rubio’s political argument for immigration reform — it will take the issue, and a Democratic advantage, off the table — has collapsed, as certain conservatives have increasingly convinced themselves that Latino voters are ancillary to their political success. All they have to do, the argument goes, is increase turnout among white voters.

If this holds, it could lead House Republicans to commit to their rejection of immigration reform and damage Rubio’s standing with the party — a dangerous thing, given his presidential ambitions. Which might explain his decision to introduce a tough, late-term abortion ban in the Senate. Here’s the Weekly Standard with more:

Senator Marco Rubio (R-Fla.) today agreed to be the lead sponsor of a Senate bill to ban abortion after an unborn child is 20 weeks old. A similar measure passed the House last month and a state version is now being debated in the Texas legislature, where it is likely to be approved.

With Rubio’s presence, the bill is certain to gain enormous media attention and thus more national visibility for the issue of limiting late term abortions. Right-to-life groups have urged Rubio to take the lead on the issue, believing he would be the strongest possible advocate in the Senate. Several sources confirmed he’d agreed.

The thinking is straightforward: If immigration reform fails, Rubio will have to rebuild trust and stature with a large number of conservatives. Opposition to abortion — given its constant throughout the GOP coalition — is the easiest path to take. By championing abortion restrictions, Rubio will attract the attention of pro-choice advocates and the acclaim of their pro-life counterparts. It’s not a bad strategy, and given the intensity of conservative opposition to abortion, it will probably work.

Jamelle Bouie is a staff writer at The American Prospect, where he writes a blog.