Let’s pay a little attention to O’s newest cabinet appointee, in case you missed the news this weekend.

President Obama is preparing to nominate Mayor Julián Castro of San Antonio as his new secretary of housing and urban development, elevating one of his party’s Hispanic rising stars as part of a cabinet shuffle that has possible implications for the 2016 presidential race, Democrats informed about the plans said on Saturday.

Mr. Castro, who has often been mentioned as a potential vice-presidential candidate for the Democrats, would take the place of Shaun Donovan, who is to become director of the Office of Management and Budget. That job is being vacated by Sylvia Mathews Burwell, whom Mr. Obama tapped to be secretary of health and human services and who seems headed to Senate confirmation…

Mr. Obama had tried to lure Mr. Castro to the cabinet before. After the 2012 election, the president approached the mayor about serving as transportation secretary, but Mr. Castro, whose third term ends next year, indicated that he preferred to stay in San Antonio. He also passed on the chance to run for governor of Texas this year.

To put this in context, you must must must read Byron York’s post today on what Castro does, or rather doesn’t do, as mayor of San Antonio. It’s a figurehead role, not unlike the presidency in a parliamentary system; the responsibilities of actually running the city devolve to the city manager, the de facto prime minister. Castro doesn’t even get a regular salary for being mayor. So why is a guy like that, who won’t turn 40 until this September, suddenly being elevated to lead HUD? You know why. It’s the same reason he was chosen to deliver the keynote at the 2012 Democratic convention despite there being endless numbers of more accomplished lefties who coveted the job. He’s the Platonic ideal of a major-party national candidate: Strikingly young, to appeal to twenty- and thirtysomethings; highly credentialed, with degrees from Stanford and Harvard Law; and of course Latino, which boosts the party’s chances of getting the country’s fastest-growing demographic to turn out en masse. Essentially he’s a Latino Obama, except with much less experience. If he ends up as VP in 2016, he’d be the youngest veep since Dan Quayle (who had spent eight years in the Senate by the time he was sworn in) and indisputably the one with the thinnest resume, which means, if Hillary’s health goes south, the free world could conceivably be led circa 2018 by a guy whose main qualification was a two-year sinecure atop America’s housing bureau. But look at it this way. If they’re going to have a pure identity-politics candidate at the top of the ticket, why shouldn’t they also have one at the bottom?

I thought Cory Booker had the inside track to be Hillary’s VP, just because Democrats are nervous that black voters won’t show up in 2016 in the same numbers they did in 2008 and 2012 without a black candidate on the ticket. Looks like instead they’re going to try to goose Latino turnout, which makes sense: If black turnout falls, Latinos could be a hedge against that, and if black turnout doesn’t fall, higher Latino turnout will expand Democrats’ advantage at the polls. Besides, with both Obama and Bill Clinton campaigning for the ticket, Dems may conclude (rightly) that the Obama coalition is sturdier than everyone expects. As for the GOP, Castro’s emergence carries two important consequences. One: It’s now a mortal lock that either the top or the bottom of the Republican ticket in 2016 will feature a Latino candidate, almost certainly either Marco Rubio or Susana Martinez. (Cruz is too scary to establishment Republicans.) Before Castro, I bet some GOP leaders thought it might suffice to nominate Jeb Bush in the name of appealing to Latino voters. Not anymore. You’ve got a veep shortlist of two now, unless Rubio wins the nomination himself.

Two: This intensifies the pressure on Republicans to pass amnesty before 2016, to the point where I wonder if O deliberately timed the Castro appointment for a moment when Boehner’s at a fork in the road on immigration reform. Beltway Republicans have spent nearly 18 months talking themselves into believing that, without amnesty, they’re DOA among Latinos and thus DOA in the entire presidential election in 2016. If they’re already that nervous about being outpandered, they’re certainly not going to sit by and do nothing on immigration reform while Democrats groom a charismatic Latino candidate for the ticket. That doesn’t mean Boehner will move a bill this summer but it certainly means he’ll move something in the lame-duck or next year. Frankly, Obama’s showy move on Castro might even have bought the Speaker a few votes among wary Republicans in the House. They know what game Democrats are playing here; the more the other party does to woo Latino voters, the more GOP fencesitters will feel obliged to keep up. It’s a smart move by O, even if Castro doesn’t end up on the ticket after all.