ST. PAUL, Minn. — Delegates to the GOP national convention had scarcely settled into their seats when it was disclosed a lawyer had been hired to represent the Alaska governor in an investigation of her firing of the state's public safety commissioner.

Then the other shoe dropped.

John McCain's freshly announced running mate, Sarah Palin, said Monday her 17-year-old unmarried daughter was five months pregnant, leaving the McCain campaign defending his choice and the thoroughness of the background check of the little-known Alaska governor.

It was also revealed Monday that Palin's husband, Todd, had been arrested for drunken driving two decades ago.

The man who led McCain's vice presidential search team said he thought everything that came up as a possible red flag during the background check had now been made public.

"I think so," Arthur B. Culvahouse Jr. told The Associated Press. "Yes. I think so. Correct."

The revelations threatened to steal any remaining thunder from Day One of the Republican National Convention, which already was overshadowed by Hurricane Gustav — and brought unwanted attention to the 44-year-old governor, a self-described "hockey mom" with little experience on the national stage.

The GOP convention had already been scaled back because of the hurricane, and just three days after McCain named Palin as his vice presidential running mate.

"Life happens," said McCain adviser Steve Schmidt, talking about the pregnancy story.

"An American family," added colleague Mark Salter.

In a brief respite from partisanship, Democratic rival Barack Obama weighed in: "I think people's families are off limits and people's children are especially off limits."

McCain aides said the announcement about the pregnancy of Palin's daughter Bristol was aimed at rebutting Internet rumors that Palin's own youngest son, born in April, was actually the daughter's

The pregnancy statement, attributed to Sarah and Todd Palin and released by the campaign, said that Bristol Palin would keep her baby and marry the child's father, identified only as a young man named Levi. The baby is due in late December.

"Our beautiful daughter Bristol came to us with news that as parents we knew would make her grow up faster than we had ever planned. We're proud of Bristol's decision to have her baby and even prouder to become grandparents," Sarah and Todd Palin said in their brief statement.

Reactions of Utah delegates were sympathetic.

Lt. Gov. Gary Herbert said that he did not think it disqualified her to be a vice president or that it should even be used politically.