The nation’s first black president has a secret weapon when it comes to turning out black and Latino votes: An old white guy.

Vice President Biden, for the second time in three days, delivered a stemwinder in front of a group of minority voters that had the crowd eating it up. On Tuesday, it was his keynote address to the National Council of La Raza in Las Vegas, and on Thursday it was his speech in front of the NAACP convention in Houston.

Biden’s rapport with the NAACP crowd was evident from the outset Thursday. He began things by noting that he was a lifetime member of the group, was once the “only white guy on the east side,” and giving a shout-out to an NAACP official he affectionately called “Mouse.”

From there, he pivoted between talking about the successful mission to kill Osama bin Laden, Republican obstructionism, Obama’s health-care law and Republican efforts on Voter ID.

By the end of the speech, Biden could feel the moment.

“There’s a lot more to say, but this is preaching to the choir,” Biden said. He then began to wrap up his remarks, and got booed for doing so; the crowd clearly wanted more.

Biden’s star turn in front of the NAACP crowd tells us a couple things.

First, it shows that he’s a valuable asset when it comes to the Obama campaign’s efforts to turn out minority voters. Yes, it was a friendly crowd to begin with, but enthusiasm matters.

Polls have shown Obama leading by wide margins among both black and Latino voters, and it’s a foregone conclusion that African-American voters, in particular, will continue to vote in lockstep for the first black president (preaching to the choir, indeed).

The question, though, is how these normally low-turnout demographics turn out in the 2012 election. Latinos, in particular, concern Democrats because they have shown a willingness to stay home and they have fallen out of love, to some degree, with Obama.

Obama has also shown plenty of rapport with these groups, of course, but having a No. 2 that you can trust to stand in is a tremendous luxury. And Biden’s easy speech in front of the NAACP crowd showed that he’s not just going to be an attack dog (the more traditional role of the vice president), but also a pretty formidable cheerleader for a president who badly needs someone to pump up the crowd.

Secondly, it’s hard to look at the speech Biden gave Thursday and not see a 2016 presidential candidate.

The fact is that Biden has always struggled because people didn’t see him as a real presidential contender. While generally well-regarded in his party and by the media (in spite of his gaffes), Biden’s real problem in the 2008 campaign was that he was never able to get a real shot at the main stage.

As a sitting vice president, though, and having delivered speeches like this, it’s going to force people to reevaluate his fortitude and whatever presidential aspirations he might have.

This is not to say that he’s going to be a front-runner for the Democratic nomination in 2016 or even that he will run (though it seems like he wants to). But it does show what Biden can do when he’s at his best. He’s a talented politician, and when he puts it together, it works.

Biden’s speech Thursday will definitely change some people’s minds about his role in the 2012 and 2016 campaigns.