In what could be another huge upset for an incumbent, Alaska Sen. Lisa Murkowski appeared to be losing to Tea Party favored Joe Miller in a heated fight that pitted one mama grizzly against another -- Sarah Palin.
The votes were still being counted in Alaska and the race was too close to call Wednesday morning. But with 98 percent of precincts reporting, Murkowski was trailing behind Miller by about 2,000 votes.
However, more than 7,500 absentee ballots still need to be counted and that may not begin happening until next Tuesday.
Murkowski, who is seeking a second term, is supported by virtually the entire Republican establishment. But Palin, who ousted Murkowski's father in 2006 to become Alaska's governor, loomed large in the race even though she was not on the ballot. A last-minute push by Palin and her husband Todd elevated Miller, whose rallies grabbed headlines in July for theirgun-toting supporters.
Palin accused Murkowski of supporting the Obama administration's agenda and siding with Democrats on key issues.
"She's waffled on the repeal of Obamacare, co-sponsored cap-and-trade and voted for TARP," Palin said in recorded telephone message for Miller. "Joe Miller has the right ideas for Alaska."
Miller was also supported by a bevy of conservative activists and radio hosts, including California-based Tea Party Express and conservative commentators Laura Ingraham and Mark Levin.
On the flip side, it was a good night for another incumbent. Arizona Sen. John McCain breezed to victory against former Rep. J.D. Hayworth, a talk radio host mounting a challenge from the right against the 2008 Republican presidential candidate.
McCain, who took no chances in his primary fight, led Hayworth by 51 percent of the vote.
McCain spent $21 million on the primary, a staggering sum for a candidate who was his party's nominee for president just two years ago, but the seriousness with which McCain took the primary, altering some of his more independent positions to appeal to a conservative base, helped him handily defeat Hayworth.
"This was a tough, hard-fought primary," McCain said in his victory speech. "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."
McCain, who has never lost a statewide race, is the odds-on favorite to win a fifth term come November. He has promised to "fight with every ounce of strength and conviction" against his Democratic challenger Rodney Glassman.
In another high-profile race in Arizona fraught with controversy, the son of former vice president Dan Quayle, Ben, clinched the Republican nomination in the 10-way primary for the House seat.
Buyoed by a last-minute push by his parents that included an appeal defending their son, Quayle sailed to the forefront with 23 percent of the vote. The outspoken Obama critic earned some heat for allegedly contributing to a racy website in the past.
In the Sunshine State, a Democratic billionare stumbled in his quest to become a senator and a Republican multi-millionaire scored an upset in his quest for the Republican nomination to governor, making it a mixed night for uber-rich candidates there.
Rick Scott, the multi-millionaire former hospital chain executive, had trailed in recent polling, but defeated Florida Attorney General Bill McCollum 46-43 after a campaign that turned ugly in recent weeks.
In the other hotly contested and nationally scrutinized Florida race, Jeff Greene, the insurgent billionaire who poured tens of millions of his own money into the Democratic primary was unable to defeat Rep. Kendrick Meek, a South Florida lawmaker with a political pedigree. Meek got more than 57 percent of the vote.
"The pundits thought this seat could be bought," Meek said in a message to supporters. "Our critics wrote us off."
Meek will face off against Republican Marco Rubio, the Tea Party favorite and former State House speaker, whose strong conservative candidacy drove moderate Gov. Charlie Crist out of the Republican party earlier this year when his public backing of President Obama's economic policies made him unpalatable to Florida Republicans.
Rubio faced only token opposition in the Republican primary.
But Crist has stayed in the Senate race as an independent, setting up a three-way contest in November.
Despite campaign help for Meek from former President Bill Clinton and President Obama, some Washington Democrats had secretly been hoping for Greene to pull out a victory because it would have helped Crist, who they hope could help them maintain their majority in the Senate.
Recent polling shows Rubio and Crist neck and neck, with Meek drawing between 15 and 20 percent of votes in a hypothetical general election.
"While Meek is an unabashed liberal, Gov. Charlie Crist has made it clear that he will simply say or do anything to win an election, as his positions seem to move wherever the most politically expedient wind blows," said Sen. John Cornyn, R-Texas, who chairs the National Republican Senatorial Committee in a memo previewing their argument for Rubio leading into the fall.
Greene's brief candidacy provided salacious story lines; he brought a big personality into the race and was dogged by, among other things, his personal friendship with the former boxer Mike Tyson, who was the best man at Greene's wedding, and his former roommate Heidi Fleiss, notorious as the Hollywood Madame.
Then there's his yacht called the "Summerwind," where there may or may not have been scandalous parties in far-flung and exotic locations.
Rick Scott, who like the billionaire Greene, who bankrolled much of his own primary campaign and spent $50 million of his own funds, narrowly defeated Florida Attorney General Bill McCollum.
The race has veered both candidates to the right. Scott, who became a national figure when he organized a group that spent millions opposing the passage of Democrats' Health Reform Law, he unveiled an immigration proposal that would be even stricter than the controversial Arizona law that requires immigrants to carry proof of legal residency.
But Scott has struggled to distance himself from a massive $1.7 billion Medicare fraud fine -- the largest ever -- levied against the Columbia/ HCA health care company, when he was CEO.
Florida CFO Alex Sink, who easily won the Democratic primary, had stayed above the fray, but whomever she meets in November will be bloodied by the primary and ready for a fight.
The five-way Democratic race for Vermont governor, the most contested race in the state, is too close to call.
With 89 percent reporting, state Senate President Pro Temp Peter Shumlin was ahead of former Lt. Gov. Doug Racine by 121 votes. Secretary of State Deb Markowitz was just 930 votes behind Shumlin.
The winner will face GOP Lt. Gov. Brian Dubie, who was uncontested in the Republican primary.
ABC News' Amy Walter and Jonathan Karl contributed to this report.