Julian Castro has both a blessing and a curse: He's President Obama's pick to be secretary of Housing and Urban Development, but most people are focused on what job he'll take after HUD.

When Obama nominated the 39-year-old San Antonio mayor, the universal footnote was that the soon-to-be youngest member of the president’s Cabinet was using the post as a stepping stone to a future presidential ticket.

And Castro’s surrogates are hardly trying to lower expectations.

Henry Cisneros, HUD secretary under President Bill Clinton -- and Castro's mentor -- has been prepping the mayor for his ascension to Washington, framing the former lawyer's ambitions in grand terms.

“Who is not looking to advance?” Cisneros mused during an interview with the Washington Examiner. “You can’t fault a person for that. That’s the name of the game.

“The bigger question,” Cisneros added, “is do you make a difference when you have this kind of opportunity?”

But how will Castro, a relative unknown, build his brand as part of an administration approaching lame-duck status, at an agency that has been overshadowed during the Obama years?

“It's a bit naive to think he's on the fast track to the vice presidency,” conceded a senior Democratic strategist with close ties to the White House. “I love Julian, but let's face it, not too many voters are aware of the inner workings of an agency like HUD.”

The Senate is expected to confirm Castro soon after the upper chamber returns from its July 4 recess.

The incoming HUD secretary was re-elected to his third, two-year term as San Antonio mayor in 2013 after becoming the youngest city councilman in San Antonio history at age 26. Another bonus for Castro’s political narrative: His twin brother, Joaquin, represents western San Antonio in the House.

The Obama appointee, born in San Antonio, received an undergraduate degree from Stanford University and a doctorate from Harvard Law School. He is married with a young daughter.

Castro, who splashed onto the national stage with his Democratic National Convention keynote address in 2012 -- when he was dubbed the “Hispanic Obama” -- certainly has loftier political goals than his predecessor, the wonkish Shaun Donovan, who is taking over as director of the Office of Management and Budget.

The president's housing agenda has remained on the back burner, with Obama instead choosing to focus on the implementation of his signature health law, immigration reform and growing instability abroad.

However, Castro would be tasked with spearheading the administration's plan to wind down mortgage buyers Fannie Mae and Freddie Mac -- an effort that has alarmed some Democrats who fear that lending costs could skyrocket without the backstop.

"I absolutely believe that there are better alternatives than what we have in place with this duopoly and with this conservatorship," Castro told a Senate panel reviewing his nomination in recent weeks.

Castro also would tackle the Federal Housing Administration, a government mortgage insurer that drew $1.7 billion in taxpayer funds last year. As HUD secretary, Castro would try to explain how the administration can jump-start the housing market without relying on taxpayers.

Asked about the FHA, Castro told senators he was “committed to the historic mission to ensure that first-time homebuyers, that folks of modest means who are creditworthy, that they have the opportunity to reach the American dream of homeownership.”

But taking on a federal bureaucracy like HUD would be a heavy lift for Castro. San Antonio employs a form of government in which the city manager is most responsible for daily operations and the mayor is weak -- Castro made just a few thousand dollars annually in the post but banked more than $200,000 last year from a book advance and speaking fees.

“I honestly think he got bored with being mayor — it’s a very weak position in that city,” said Austin-based Republican strategist Matt Mackowiak.

“He really is the biggest Democratic star in Texas,” the GOP consultant added. “I think he's bigger than [Texas governor candidate] Wendy [Davis]. This is more about him positioning himself to be a finalist for vice president, taking a short cut to the top.”

Cisneros, also a former San Antonio mayor turned HUD secretary, heavily lobbied Castro to take a job in the Obama administration. Castro was reportedly Obama's pick for transportation secretary after the 2012 election but decided not to make the Washington plunge.

Up against daunting odds to win statewide office, Castro ultimately changed his mind about joining team Obama.

Cisneros, who recently hosted Castro at his Texas home, is uniquely suited to counsel the new “rising star” on the perks -- and pitfalls -- of the job. Cisneros pleaded guilty to a misdemeanor for lying to the FBI about payments to a former mistress, ending any hopes that he might be picked for the national ticket.

“I gave him a map of the territory,” Cisneros said of his guidance.

“It helps to be a mayor," he explained. “The HUD secretary is the principal emissary from the president to the cities, and the housing sector did not come back like it did following previous recessions. This will be a very important job and carry some cache in the Cabinet."