ST. PAUL, Minn. (AP) -- Claiming her historic place on the Republican ticket, vice presidential candidate Sarah Palin mocked Barack Obama's experience and promise of change Wednesday night and pledged to help John McCain upend the Washington establishment.

"In politics, there are some candidates who use change to promote their careers," she said in a barbed reference to Obama's campaign theme. "And then there are those, like John McCain, who use their careers to promote change," she added in remarks prepared for her prime time address to the Republican National Convention.

In a second unmistakable jab at McCain's White House opponent, Palin traced her career as mayor of Wasilla, Alaska, to governor of her state, adding: "I guess a small-town mayor is sort of like a `community organizer,' except that you have actual responsibilities."

As a young man, Obama did a stint as a community organizer.

The Alaska governor had top billing at the convention on a night delegates also lined up for a noisy roll call of the states to deliver their presidential nomination to McCain.

Palin, 44, also jabbed at the news media, which have raised convention week questions about her background and her family, including her 17-year-old unmarried, pregnant daughter. "Here's little news flash for all those reporters and commentators: I'm not going to Washington to seek their good opinion - I'm going to Washington to serve the people of this country."

McCain arrived in the Republican National Convention city earlier in the day to accept the prize of a political lifetime. Instantly, defended his choice of a running mate, saying she was ready to serve as commander in chief after less than two years as governor of Alaska.

"Oh, absolutely," he said in an ABC interview.

"Having been the governor of our largest state, the commander of their National Guard, she was once in charge of their natural resources assets actually, until she found out there was corruption and she quit. ..."

McCain bounded down the steps of his chartered campaign jet at midday into the arms of his extended personal and political family. His wife Cindy was first in line, then their children, then Palin.

McCain hugged his running mate and greeted her husband Todd, known as the "First Dude" of Alaska. Then, cameras recording each gesture, the Arizona senator lingered when he reached the couple that has been the focus of so much convention-week attention, 17-year-old Bristol Palin and the father of her child, Levi Johnston, 18.

McCain's remarks dovetailed with an effort by his campaign to depict Palin's critics as out to destroy the 44-year-old governor, the first female running mate in party history.

The presidential nomination his after a decade of struggle, the 72-year-old McCain swung the spotlight Palin's way on the convention's third night.

While she readied the speech of her career, McCain's top strategist, Steve Schmidt, complained about a "faux media scandal," generated, he said, by "the old boys' network that has come to dominate the news establishment."

Equally insistent, former Massachusetts Gov. Jane Swift said, "Just like me, we can assume Gov. Palin loves her children, and we can just leave it at that." It was a reference to the vice presidential running mate's daughter, unmarried and pregnant.

Thrust into the national spotlight less than a week ago, the 44-year-old Alaska governor made a brief visit to the Xcel Center to prep for her prime time address to delegates - already on her side - and a prime time TV audience counted in the millions.

Little is known nationally of her views, although a video surfaced during the day of a speech she made at her church in June in which she said U.S. troops had been sent to Iraq "on a task that is from God."

In his interview with ABC, McCain said of Palin, "I mean, this person is going to come to Washington and, I'm telling you, the `old boys' network,' they better look out because change is coming."

He took another slap at Democratic rival Obama, saying Americans don't want "somebody who has - who is, frankly, necessarily gone to Harvard or an Ivy League school. She probably hasn't been to a Georgetown cocktail party," he added.

McCain 's campaign gave speaking turns to three of his former rivals in the primaries of last winter and spring, and they used the opportunity to praise him and warn of the consequences of a defeat.

"Maybe the most dangerous threat of an Obama presidency is that he would continue to give madmen the benefit of the doubt," former Arkansas Gov. Mike Huckabee said in remarks released in advance.

Former Massachusetts Gov. Mitt Romney accused Obama of ducking several questions at a recent joint appearance with McCain, who he said "hit the nail on the head: radical Islam is evil, and he will defeat it.

Former New York City Mayor Rudy Giuliani added that Palin "has more executive experience than the entire Democratic ticket," which includes Obama and Delaware Sen. Joseph Biden, a veteran of more than three decades in the Senate.

Not everyone was quite on message, though.

"I think that Gov. Palin and Sen. Obama do not have extensive experience in government," Sen. Arlen Specter of Pennsylvania told reporters. He said she has potential, and judged Obama a "political phenomenon, no doubt about it."

Whatever Palin's impact on the race, McCain's story was among the most arresting in recent presidential politics.

The son and grandson of admirals, he had a rebellious youth by his own account, running up a healthy ledger of demerits at the Naval Academy. Shot down over Vietnam, he was held and tortured for more than five years before his release. Along the way, he turned down an offer of early freedom from captors eager for a propaganda boost.

Elected to Congress in 1982, he moved to the Senate in 1986 as a Reagan Republican. Soon singed by the "Keating Five" scandal, involving the savings and loan industry, he shifted course.

He began carving out a maverick's role, championing legislation to reduce the influence of money in politics and fighting wasteful government spending.

Increasingly over the years, he parted company with fellow Republicans on issues as diverse as tobacco, health care, immigration, judicial nominees, a commission to investigate the Sept. 11 terror attacks, the use of torture in interrogations and more.

He first ran for president in 2000, but lost the GOP nomination to George Bush in a bitter struggle.

As the early front-runner eight years later, he watched helplessly as anger with the Iraq war drained him of the support of independents while conservatives deserted because of legislation giving illegal immigrants a pathway to citizenship.

Out of money - but not hope - he pared back his campaign and persevered. When Huckabee defeated Romney in the leadoff Iowa caucuses, it opened the door for McCain to win the New Hampshire primary five days later.

He did, and despite a chronic shortage of funds, methodically dispatched his rivals, one by one, before clinching the nomination with a series of big-state Super Tuesday wins on Feb. 5.

Never a favorite of conservatives, he worked slowly to draw them to his side, and his selection of Palin was a surprising stroke.

Social conservatives greeted her pick enthusiastically - support that coalesced in the ensuing days as her daughter's pregnancy became known.

While McCain himself appeals to independents, strategists said they hoped Palin's presence on the ticket would gain a second look from conservative Democrats who sided with New York Sen. Hillary Rodham Clinton during her failed candidacy earlier in the year.