Sen. Marco Rubio says that if Senate Majority Leader Harry Reid brought the immigration reform bill that Rubio sponsored last year to the floor for a vote now, he would vote against it. Rubio explained that passing his immigration bill wouldn’t be productive, and thus the vote would only be for show.

But if “unproductive” and “show votes” automatically deserved a “no,” our solons would rarely vote “yes.” If his bill was meritorious last year, as Rubio believed, it is meritorious now, and should be treated accordingly.

Rubio also claims that he doesn’t regret his support for his immigration reform bill last year, but it’s pretty clear that he does. After all, that bill turned out (thankfully) to be unproductive.

More importantly, if Rubio hadn’t supported amnesty-style comprehensive immigration reform, he would probably be the front-runner for the Republican presidential nomination. At a minimum, he wouldn’t feel compelled to fast talk his way out of the political damage he inflicted on himself by leading the charge for amnesty.

Amnesty-style comprehensive reform isn’t the only immigration issue as to which Rubio is flipping. There is also the matter of “dreamers.”

The Wall Street Journal reports that Rubio says he wants to end a program called Deferred Action for Childhood Arrivals, which gives safe harbor and work permits to some people brought to the U.S. as children. During a speech earlier this week, he told young illegal immigrants that they are hurting their cause.

We are a sovereign country that deserves to have immigration laws. You’re doing harm to your own cause because you don’t have a right to illegally immigrate to the United States.

Rubio then waited while security escorted the “dreamers” out of the room.

Rubio took a very different approach during a 2012 event. At that time, according to the Journal, Rubio responded to “dreamers” by saying:

These young people are very brave to be here today. They raise a very legitimate issue. I don’t want them to leave. I want them to stay.

Rubio explained this about face by complaining that the “dreamers” aren’t giving him enough credit for trying to help him. As Sonny Corleone would say, he “is taking this very personal.”

The first law of holes dictates that Rubio stop digging. But presidential politics are impelling him to violate that law.

When Rubio surveys the potential presidential field, he surely sees that no Republican stands out. Why else would we be hearing so much talk about another Mitt Romney bid?

In addition, Rubio surely remembers that, not long ago, he stood out. Couple this with the fact that, like Barack Obama, Rubio seems to have infinite faith in his ability to talk his way out of tight spots, and you get the embarrassment of his latest immigration squirming.

It may well cause some conservatives to take another look at Rubio. But when I look at him, I continue to see a politician whom it is difficult to trust.

For more on the tortured history of Rubio on immigration, see here, here, and here.