But back home, she has cheered the work of a tiny party that long has pushed for a statewide vote on whether Alaska should secede from those same United States. And her husband, Todd, was a member of the party for seven years.
The Alaskan Independence Party, founded in 1978, initially promoted "the Alaskan independence movement." But now, according to its website, "its primary goal is merely a vote on secession."
McCain campaign spokesman Tucker Bounds said Tuesday that Palin did not support splitting Alaska off from the rest of the country. He sidestepped the question of whether she favored a statewide vote on secession.
"Gov. Palin believes that every American is entitled to their point of view, and their political beliefs," he said.
Bounds also did not directly answer the question of whether her husband supported the secession of Alaska.
"I can tell you that Mr. Palin is a proud American," Bounds said. "And he's excited that his wife has joined John McCain to reform Washington and make government work more effectively for all Americans."
For all but two months from 1995 to 2002, the governor's husband was registered as an Alaskan Independence Party member, according to the Alaska Division of Elections.
With McCain's campaign emphasizing patriotism -- his latest slogan is "Country First" -- the Palins' links to a party founded by the late secessionist gold miner Joe Vogler could prove awkward.
"I'm an Alaskan, not an American," Vogler is quoted as saying elsewhere on the party’s website. "I've got no use for America or her damned institutions."
The party supports a plebiscite on four options that it says Alaskans were entitled to vote on before becoming a state in 1959: Form a sovereign nation of their own, become a state, accept commonwealth status similar to Puerto Rico's, or remain a U.S. territory.
Leaders of the party say many of its 13,681 registered members have joined out of frustration over restrictions that the federal government has placed on the use of its vast land holdings in Alaska. Beyond the secession vote, the party also advocates gun rights, home schooling and abolition of property taxes.
A question-and-answer page on its website asks, "Aren't most Alaskan Independence Party members a bunch of radicals and kooks?"
"The party has its share of individualists, in the grand Alaskan tradition," the answer says. "No longer a fringe party, the AIP is a viable third party with a serious mission and qualified candidates for elected offices."
Less than 3% of the state's 479,721 registered voters are members of the party.
An AIP high point came in 1990, when Walter J. Hickel -- a Republican governor of Alaska in the late 1960s -- won the job again as the Alaskan Independence Party's candidate. But he returned months later to the GOP.
Palin and her husband attended the party's 1994 convention at a Best Western in Wasilla, Alaska, said former Chairman Mark Chryson, a computer repairman who is now the party's webmaster.
A former mayor of Wasilla, Palin also spoke to the party's convention in the same hotel in 2006 when she was running for governor, Chryson said.
Dexter Clark, an Alaskan Independence Party vice chairman, brought up Palin's ties to the group in videotaped remarks to the second North American Secessionist Convention in October in Chattanooga, Tenn.
"She was an AIP member before she got the job as the mayor of a small town," Clark told the group. "That was a nonpartisan job. But you get along to go along. She eventually joined the Republican Party."
McCain's campaign distributed Palin's voter registration records Tuesday to show that she had never been a member of the AIP.
The Alaska Division of Elections confirmed that Palin had been registered as a Republican since 1982.
McCain's campaign also slammed ABC News for posting a Web story saying that Palin had been a member of the party, calling the report a "smear."