Sen. Barack Obama (D-Ill.) must commit to helping illegal immigrants achieve citizenship or else risk losing the vital Latino vote in the general election, Hispanic Democratic lawmakers are warning.

If he does not promise so-called comprehensive immigration reform, the lawmakers say, the only other way to win over Hispanic supporters of his erstwhile rival, Sen. Hillary Rodham Clinton (N.Y.), may be to pick her as his running mate.

They carefully avoided calling explicitly for Clinton’s selection as the party’s vice presidential nominee, but some indicated that her bond with Latino voters will get them to the polls in November, just as it drew them into the primaries.

“Hillary holds the entire Latino community in the palm of her hand,” said. Rep. José Serrano (D-N.Y.), whose district went heavily for Clinton.

But Sen. John McCain (Ariz.), Obama’s Republican opponent, is also liked by Latinos. He co-sponsored with Sen. Edward Kennedy (D-Mass.) the immigration bill that the CHC is demanding, which would put the country’s 12 million illegal immigrants on a path to citizenship. And he did not buckle under pressure to abandon that position during the GOP primary.

Cecilia Munoz, the senior vice president of research, advocacy and legislation with the National Council of La Raza, said whether McCain can win over large enough numbers of Latino voters is “still an open question.”

“But Latinos are brand-loyal, and after the Clinton brand, the McCain brand is the second-strongest among Latinos because of his military service and his immigration record,” Munoz said.

CHC Chairman Rep. Joe Baca (D-Calif.) said that if Obama chooses someone other than Clinton, it will not be a deal-breaker for Latinos.

“But I hope he does make the right decision and picks someone who draws together our communities,” Baca said. “Is that Hillary? I think she’s certainly one of those candidates.”

While Obama won the Latino vote in his home state of Illinois and in Colorado, and stayed competitive in New Mexico and Arizona, he was walloped among Latinos — 64 percent to 24 — throughout the 24 contests making up Super Tuesday. In California, Clinton won over Latinos 67 percent to 29.

Latino voters comprised 30 percent of California Democratic primary voters, an increase of 17 percent from 2004. In Texas, the number of Latinos voting in the Democratic primary rose 8 percent, to 32 percent of the electorate, according to the Pew Hispanic Center.

In harnessing such enthusiasm, Baca also said that the CHC will be looking — but not necessarily asking — for Obama to make as strong of a pledge as Clinton did to putting comprehensive immigration reform on his “first 100 days” agenda.

“He says he wants to, but he needs to show that he’s serious about taking it up.”