President Obama has nominated San Antonio Mayor Julian Castro as secretary of the Department of Housing and Urban Development, or HUD.

Now, if you wanna be HUD secretary, there are a few things you should know. No. 1: HUD doesn’t have a say in the biggest federal housing initiative, the housing deductions in the federal tax code.

“HUD has not traditionally been one of the most powerful cabinet agencies,” says Robert Van Order, a former HUD economist who now teaches finance and economics at George Washington University. Van Order points out a second challenge facing Castro: HUD’s budget has been cut. 

Still, Van Order says, housing is important, especially now when it’s so key to our economic recovery. 

“And so the secretary of HUD has to represent housing as a part of the discussions of what legislation ought to be,” he explains.

Henry Cisneros, who was HUD secretary during the Clinton administration, says the top boss at HUD still sets priorities for housing.

“A HUD secretary can make a difference,” he says.  “Tweaking policy and budgets. Working with the Congress.”

And Cisnerso says, don’t forget the Federal Housing Administration , or FHA, is part of HUD. It insures housing loans for people banks pass over.  And during the housing crisis, it was “essentially the only source of credit for first-time homebuyers in particular, but minority homebuyers as well,” says Erika Poethig, who worked on policy development at HUD and left last year to join the Urban Institute. 

Poethig says Castro will have plenty of work to do as the housing recovery sputters along.  

That is, pending a Senate confirmation vote.