Hillary Clinton-Julian Castro 2016: an already inevitable Democratic ticket?

Democrats are grooming Housing Secretary Julian Castro for national office. If Marco Rubio is on the Republican ticket (and even if not), Mr. Castro may be the Democrats' obvious answer.

All the talk about GOP Sen. Marco Rubio’s prospects as a presidential candidate raises an inevitable question for Democratic favorite Hillary Rodham Clinton: If she’s the nominee, will she choose a Latino as her running mate?

In 2016, having the first female presidential nominee for a major party in US history may not be enough diversity for the Democratic ticket. The Latino vote is a fast-growing, crucial piece of the American electorate for both parties. So it may, in fact, make sense for Mrs. Clinton to double down on diversity with a Latino running mate.

High on the presumed list is Julián Castro. He’s secretary of the Department of Housing and Urban Development (HUD) and former mayor of San Antonio – long eyed as a rising Democratic star, along with his identical twin, Rep. Joaquin Castro (D) of Texas.

Last May, when President Obama tapped Julián Castro to run HUD, it was clear the White House was trying to build the then-mayor’s national résumé. Mr. Obama was “excited about the mayor bringing his practical, on-the-ground success to scale at the federal level,” a White House official said at the time.

In 2012, Mr. Castro was the Democrats’ choice as the party’s national convention keynote speaker – a slot Obama used in 2004 as a springboard to national fame, and eventually the presidency.

From the moment Castro was nominated to run the housing department, the move was framed as an effort to position him for the next Democratic ticket.

From Castro’s perspective, being seen as a veep prospect could pay dividends in his work at HUD, usually a backwater for national media coverage. He is cautious about his talk of the future. But he can’t control what reporters write about him – including a recent piece in The Daily Beast that asserted, “Julian Castro is in VP training camp.”

Castro said his top goal at HUD is to implement Obama’s call to end veterans’ homelessness, and also to expand housing vouchers for victims of domestic abuse. But inevitably, he was asked about the future.

“We’ll see what happens in the years to come,” Castro told The Daily Beast’s Eleanor Clift and a handful of other reporters. “I’m trying to do a great job as HUD secretary. If you do a great job, that opens up opportunities, sometimes opportunities you don’t even see in the future.”

Clinton reportedly has long had her eye on Castro, and though they’ve met a couple of times, they don’t know each other well, Ms. Clift reports.

“With candidate Clinton, it will be about confidence and chemistry,” she writes.  

Some Democrats have expressed hope that putting Castro on the ticket could put Texas in play. That’s probably a long shot. Texas is solid red, and usually a running mate doesn’t bring many additional votes from his or her home state. (Though one exception involves Texas: In 1960, then-Sen. John F. Kennedy’s selection of Senate majority leader Lyndon B. Johnson of Texas as his running mate is widely seen as helping deliver Texas, and the election, for the Democrats.)

For the Republicans, having Senator Rubio somewhere on the ticket could help deliver Florida, the most populous battleground state and a must-win for the GOP if it wants to retake the White House. So, too, could the presence of former Florida Gov. Jeb Bush. His wife, Columba, is Mexican-born, and like Rubio, Mr. Bush speaks Spanish.

For Clinton, selecting a much younger running mate could address the generational issue that Rubio raised in his announcement speech on Monday. By Election Day 2016, Clinton will be in her late 60s and Castro in his early 40s – maybe still a tad young for veep, some analysts say, but not that much younger than Rubio.

It’s still early. Candidates have barely begun to announce. But it’s not too early to look over the horizon and see who’s out there and imagine what American leadership could look like in less than two years.