ST. PAUL (Reuters) - Sarah Palin has dominated the Republican convention for days without saying a word, but on Wednesday she takes the spotlight with a prime-time speech that will introduce her to American voters and try to answer questions about her experience and life story.

Since John McCain made the virtually unknown Palin his choice for vice president, the Alaska governor has been the center of a media storm fueled by disclosures about her unmarried teenage daughter’s pregnancy, a probe into her role in an Alaskan official’s firing and questions about her political record.

Palin’s anti-abortion and pro-gun history have excited conservatives and party activists but the appearance on Wednesday will be the first chance for voters nationwide to judge her for themselves.

It comes just five days after McCain shocked the U.S. political world by introducing the 44-year-old first-term governor and former mayor of Wasilla, Alaska, as his running mate at an Ohio rally.

“She already has more executive experience than the entire Democratic ticket,” Rudy Giuliani, the former New York mayor, said in remarks prepared for delivery to the convention on Wednesday. “She’s led a city and a state.”

McCain, 72, an Arizona senator, and Palin will face Democrat Barack Obama and his vice presidential running mate, Delaware Sen. Joe Biden, in the November 4 presidential election.

The McCain campaign released a television ad comparing Palin’s experience with the qualifications of Obama, a first-term senator from Illinois. “She’s earned a reputation as a reformer,” the ad’s narrator says. “His reputation? Empty words.”

Obama told voters in Ohio that the Republicans had barely mentioned the faltering U.S. economy at their convention session on Tuesday. Polls show voters rank the economy as the top election issue.

“All these speakers came up, you did not hear a single word about the economy. Think about it. Not once did people mention the hardships that folks are going through,” Obama said at a campaign stop in New Philadelphia, Ohio.

McCain arrived in the St. Paul area on Wednesday and was greeted by his family and Palin’s family. Among those meeting him were Palin’s pregnant daughter Bristol, 17, and her boyfriend. McCain briefly chatted with both.

Palin, the first female Republican vice presidential nominee, has stayed out of the public eye in Minnesota for two days while the revelations about her family and record in Alaska surfaced. She has yet to give a news interview or news conference.

PREPARATION

She has been preparing for her address with McCain aides. “This speech is about a record of reform, her case for Sen. McCain’s election and a close-up look at an individual with both hands on the steering wheel of America’s energy economy,” McCain aide Tucker Eskew said.

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The speech will give Palin a chance to move past the issue of her daughter’s pregnancy and the Alaska probe into whether she abused her power in having a public safety commissioner fired, although it is unclear if she will directly address either topic.

Carly Fiorina, a senior McCain campaign adviser, and other Republican women said the media storm over Palin was a result of sexism. “The Republican Party will not stand by while Sarah Palin is subjected to sexist attacks,” Fiorina told a news conference.

The furor over Palin has raised questions about McCain’s judgment and the depth of the investigation that preceded her selection, and could put a dent in McCain’s efforts to build momentum heading out of the convention.

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McCain aides said they would answer no more questions about the process. “This vetting controversy is a faux media scandal designed to destroy the first female Republican nominee for vice president of the United States, who has never been a part of the old boys’ network,” McCain adviser Steve Schmidt said.

Much of Monday’s convention schedule was delayed by Hurricane Gustav’s assault on the Gulf Coast, but the gathering resumed on Tuesday with the passing of leadership in the party from President George W. Bush to McCain.

Bush did not attend the convention, but praised McCain, who had been his rival in a bitter presidential nominating battle in 2000.

“He’s not afraid to tell you when he disagrees. Believe me, I know,” Bush told the convention in a brief speech via satellite from Washington.