WASHINGTON - Veteran Sen. John McCain sailed to nomination for a fifth term Tuesday over an Arizona challenger with tea party support, but big-spending political novice Rick Scott beat an insider in Florida's Republican gubernatorial primary as voters split on the merits of establishment candidates vs. outsiders.

In other big-name races, Rep. Kendrick Meek prevailed for Florida's Senate Democratic nomination over upstart Jeff Greene, and Sen. Lisa Murkowski of Alaska hoped voters would reward political experience as she faced a spirited Republican primary challenge 10 weeks before the general election. She was in a surprisingly close race with about a third of the vote counted.

Nominating contests in five states - Vermont also was voting, and Oklahoma held GOP runoffs - highlighted dominant themes of this unpredictable election year, including anti-establishment anger and tea party challenges from the right. But the early results indicated that if there was a single pattern to the night, it may have been the lack of one.

Just two years after reaching the pinnacle of the GOP establishment as the party's presidential nominee, McCain found himself facing a stiff Senate primary challenge by ex-radio host and former Rep. J.D. Hayworth, who tried to tap into anti-Washington sentiment coursing through the electorate. So, McCain spent more than $20 million and aggressively cast Hayworth in a negative light.

It worked, and McCain, who has never lost a statewide race, comfortably won the Republican nod in his home state. He now enters the general election as the heavy favorite to win a fifth term.

"This was a tough, hard-fought primary," McCain said at a victory party - and he quickly looked to the fall campaign. "I promise you, I take nothing for granted and will fight with every ounce of strength and conviction I possess to make the case for my continued service in the Senate."

In the extraordinarily bitter GOP race for Florida governor, Scott's financial might and criticism of his opponent as a typical tax-raising politician proved too much for Bill McCollum, the state's attorney general and a former congressman with the support of national party leaders in Washington.

Scott, who made a fortune in the health care industry and spent $39 million of it blanketing the state with TV ads, will face Alex Sink, the state's chief financial officer who sailed to the Democratic nomination. The race is certain to be one of the most hotly contested gubernatorial contests this fall.

Equally nasty was the Democratic Senate nomination fight in Florida. Meek toppled Greene, a big-spending real estate tycoon whose links to boxer Mike Tyson and former Hollywood madam Heidi Fleiss drew headlines. The four-term congressman will compete against Republican Marco Rubio, who easily secured the GOP nod, and Gov. Charlie Crist, a former Republican who is running as an independent, in November.

The general election campaign got under way immediately.

"Floridians want leaders who will fight for them all the time, not just when it helps their own political career or advances an extreme philosophy," Meek said after his victory, poking at both Crist and Rubio without naming them.

Crist, in turn, called for "independent leadership" and "not the same old partisan politicians who have brought the people's work to a halt." It was a not-so-subtle suggestion that his opponents were just that.

And the tea party-supported Rubio slapped at his rivals, saying: "If you like the direction that America is headed, if you think Washington is doing the right things, then there are two other people that are going to be on the ballot, and you should vote for one of them."

The tea party's clout was on the line in several states.

Like McCain, Murkowski of Alaska worked to overcome a challenge from a candidate backed by the fledgling coalition that questioned her conservative credentials. She faced Sarah Palin-endorsed Joe Miller, an attorney. And like McCain, Murkowski would virtually ensure her re-election with a primary victory; no Democrat is considered a serious challenger.

In Vermont, Democratic Sen. Patrick Leahy, first elected in 1974, coasted to renomination for what is likely to be a new term in November. A five-way Democratic primary for Vermont governor was too close to call; the victor could win the seat currently held by a Republican.

Also Arizona Gov. Jan Brewer, the Republican who signed the tough law designed to crack down on illegal immigration, cruised to nomination for a new term.

Tuesday's primaries played out before a backdrop of persistently high unemployment, voter disillusionment with Republicans and Democrats alike, and low job-performance standings for both Congress and President Barack Obama.

In previous contests earlier this year, voters have shown both a readiness to fire veteran lawmakers and a willingness to keep them.

The tea party has had mixed success. It won big in Nevada, Kentucky, Colorado and Utah GOP Senate contests but lost just about everywhere else.

But no matter Tuesday's outcomes, there was no question that the tea party has provided an enormous dose of enthusiasm to the GOP heading into the fall campaign. And that's dangerous for a dispirited Democratic base.