Here’s the silver lining to comprehensive immigration reform, conservatives. Having spent loads of his right-wing political capital on pandering furiously to centrist Republicans and Latino voters with amnesty, Rubio will work overtime the next two years to earn some of it back by pandering furiously to you.

We can’t be more than six months away, I figure, from him introducing a national concealed-carry bill. Which, of course, will go nowhere in the Senate, just like this one:

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 bill faces an uphill fight in the Democrat-controlled Senate and a veto threat by President Obama. But win or lose, Republicans and the leaders of the pro-life movement regard the 20-week ban as an especially favorable issue for their cause – and one that might strengthen GOP candidates in the 2014 midterm election…

At the very least, Republicans will benefit from having the Rubio-backed legislation take center stage, overshadowing controversial statements by Republican candidates in 2012 about rape and abortion. The bill provides an exception to the late term ban in the case of rape or incest and when a physical health condition puts the life of the mother at risk.

There’s little reason to think Rubio doesn’t genuinely support this, however suspicious the timing of his involvement. He’s spoken in defense of life repeatedly in his speeches. But the cynicism about his motives here — and there’s a lot of it on the right, if the comments to the Headlines item on this story are any yardstick — are inevitable after his betrayal on immigration. The lesson many border hawks have taken away from the Gang of Eight fiasco after having been so impressed by candidate Rubio’s rhetoric on amnesty is that you simply can’t trust him, even on a subject that’s hugely important to conservative voters. I trust with 95 percent confidence that he backs this abortion bill on the merits, apart from and in addition to the political benefits it has for him. Six months ago, I would have told you that confidence was 100 percent. That’s what he gets for being a liar.

Anyway, the other silver lining here is that this could end up being fertile ground for a GOP offensive on abortion, assuming some idiot somewhere in the caucus doesn’t instantly Akinize it. If the focus remains on late-term abortion, which the public overwhelmingly opposes and which forces Democrats to sweat through tragicomic explanations of why Kermit Gosnell is bad but late-term abortion is good, that’s good politics. If the focus turns to banning abortion entirely, that’s more complicated given that the public also reliably supports abortion rights during the first trimester. Obviously, the entire GOP field in 2016 will be staunchly pro-life at every stage of pregnancy, but the fact that Rubio’s pushing a bill on a hot-button social issue right now reminds me how immigration reform has also probably left him with zero room to maneuver on other social issues. The base will forgive him one big betrayal on core policy matters, but not two. Even if he ended up “evolving” privately on gay marriage a la Obama, he has no choice realistically but to remain firmly in favor of traditional marriage. In that sense, he’s the opposite of Rand Paul. Rubio spent all his conservative currency on amnesty so now he’s stuck being a by-the-book conservative on everything else whether he wants to be or not. (That’s why he lamely claimed that the big dealbreaker for him in the immigration process was extending benefits to gay spouses of legalized illegals, which the Supreme Court ended up ordering anyway.) Paul wants to save his conservative currency for more libertarian approaches to foreign policy, NSA spying, and maybe the drug war, which is why he took the very un-libertarian position of balking at the Gang of Eight bill because it didn’t have enough border security. He’ll be on board with Rubio’s new abortion bill, needless to say.