President Obama’s nomination Friday of San Antonio Mayor Julián Castro as housing and urban development secretary gives one of the Democratic Party’s fastest-rising Latino stars a new footing on the national stage.

Castro has been focused on “revitalizing one of our most wonderful cities,” Obama said in making the announcement, describing the nominee as someone who has “worked his tail off to achieve the American dream.”

The appointment would likely put Castro near the front of the line for a big job under the next Democratic president — for instance, Hillary Rodham Clinton, if that happens. It could even, if the political stars align, put him in contention to be a presidential running mate.

“Is it his final stop? It is not,” said Henry Cisneros, a longtime Castro family friend who was mayor of San Antonio in the 1980s, and then HUD secretary in President Bill Clinton’s first term.

But Castro’s nomination also suggests a fallback strategy for the charismatic, ambitious 39-year-old politician, and an acknowledgment that demographic forces are not moving to break the Republican grip on Texas as fast as many Democrats have hoped.

Castro originally sketched a different road map. It was to serve the four two-year terms allowed under San Antonio law, then run for Texas governor in 2018.

Indeed, Castro rebuffed an Obama overture to consider becoming transportation secretary in 2012, tweeting that he would “be mayor through May 2017, if the voters will have me. Zero interest in Washington.”

In 2010, his identical twin, Joaquin, then a state legislator and now a Texas congressman, told the New York Times: “To be honest, I can see a path to Washington for Julián. That path leads through the governor’s mansion in Austin. A Democrat who can win the governorship of Texas would automatically be under consideration for a spot on the national ticket.”

The theory that Texas could tilt politically rests on the rapid growth of the state’s Hispanic population and recent efforts by Democrats — including veterans of Obama’s campaign team — to bring more Latinos to the polls.

But the struggles of Democratic gubernatorial nominee Wendy Davis, a state senator who gained national attention last year by filibustering a bill on abortion restrictions, suggest that star power alone is not enough to move the needle politically in Texas.

Mark P. Jones, chair of the political science department at Rice University, said of Castro’s situation in the Lone Star State: “In many ways, it is like being an all-star on a losing team.”

The mayor’s introduction to the national spotlight came as keynote speaker at the 2012 Democratic National Convention in Charlotte. It was, in some way, an echo of Obama’s national debut eight years earlier, which the president noted in announcing Castro’s nomination to his Cabinet.

“Now, the first time most Americans heard this man speak was when he gave a speech at the Democratic National Convention almost two years ago,” Obama said. “They saw this young guy — pretty good speaker, not bad looking — talk about how America is the only place where his story could even be possible. And I watched and I thought, ‘That’s not bad.’ ”

In that 2012 convention keynote speech, Castro paid tribute to his orphaned grandmother, an immigrant from Mexico, and his community activist mother, who “fought hard for civil rights so that instead of a mop, I could hold this microphone.” The Castro brothers — neither is fluent in Spanish — both graduated from Stanford and Harvard Law School. At 26, Julián Castro became the youngest elected city councilman in San Antonio history. He was given that high-
profile speaking slot largely because of the persistence of San Antonio businessman Henry R. Muñoz III, a major Obama contributor who now is national finance chair of the Democratic National Committee.

In arguing for Castro, Muñoz lamented that Democrats have accorded few up-and-coming Hispanic leaders the stature and prominence of Republican Sens. Marco Rubio (Fla.) and Ted Cruz (Tex.), both of whom are considering 2016 presidential bids, or GOP Govs. Susana Martinez (N.M.) and Brian Sandoval (Nev.).

“There is a feeling in the Latino community that now is the time for us and that we should not stop until we have elected a Latino to the one office that has yet to be ours — and that is the Oval Office,” Muñoz said in an interview. “Julián Castro represents in many ways the future of the Democratic Party, the future of this country.”

Still, a Cabinet post is an uncertain launching pad, and it can even be perilous. Health and Human Services Secretary Kathleen Sebelius, who was well-regarded when she was governor of Kansas, did not see her reputation enhanced by the rocky rollout of the Affordable Care Act. The same has been true more recently for Eric K. Shinseki, the retired four-star general who heads scandal-
engulfed Veterans Affairs.

HUD has been a bit of a political backwater. Shaun Donovan, whom Castro was nominated to replace and who was nominated by Obama on Friday to be his budget director, is one of the less-recognizable members of the Cabinet. Nor did the HUD job bring success to Republican Jack Kemp in his 1996 vice presidential bid.

President Ronald Reagan famously failed to recognize his HUD secretary, Samuel R. Pierce Jr., in 1981, greeting him at a public event with, “Hello, Mr. Mayor.”

Castro has indicated that his preference would have been education secretary. As mayor, his biggest achievement was winning a hard-fought sales-tax increase to fund a pre-kindergarten program.

But Cisneros said the HUD post would give Castro national-policy experience and political contacts that could be crucial should the mayor find himself on the short list of presidential running mates, as Cisneros was in 1984.

Democratic nominee Walter F. Mondale’s decision to interview Cisneros that year electrified Latinos, and it was widely read as an indicator of their growing political clout. But privately, Cisneros recalled, Mondale told him it was “highly unlikely that, as a mayor, I would be selected.”

Ultimately, Mondale opted for a different history-making demographic play, tapping little-known New York congresswoman Geraldine A. Ferraro as his running mate. Their ticket lost 49 states.