PHOENIX – Sen. John McCain routed conservative challenger J.D. Hayworth on Tuesday in a Republican primary in what could be the final campaign for the former GOP presidential nominee.

McCain spent more than $20 million to beat back an aggressive challenge from Hayworth, who relentlessly attacked the senator for his shifting stance on immigration and sought to tap into the anti-incumbent rage that has taken down other lawmakers in 2010.

The race was one of several primary elections around the country.

Two years after his bitter loss in pursuit of the White House, the 73-year-old McCain now begins a final 10-week push and will be the heavy favorite. The Democratic race was still undecided, but whoever emerges will have an uphill fight in heavily conservative Arizona.

Arizona Republican Gov. Jan Brewer, meanwhile, is headed to the general election after handily winning a contest marked by a surge in her popularity after she signed a tough law targeting illegal immigration. Brewer will meet Democrat Terry Goddard in the November race.

Goddard, Arizona’s attorney general, was unopposed for his party’s nomination.

In Florida, political novice Rick Scott pushed past veteran Bill McCollum to win Florida’s Republican gubernatorial primary, and Rep. Kendrick Meek prevailed in the state’s Senate Democratic nomination over upstart Jeff Greene as voters split on the merits of establishment candidates vs. wealthy outsiders.

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 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.

In an equally nasty Senate race, Meek toppled Greene, a big-spending real estate tycoon whose links to boxer Mike Tyson and former Hollywood madam Heidi Fleiss drew headlines, in the Democratic Senate nomination fight. 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.

In Vermont, Democratic Sen. Patrick Leahy, first elected in 1974, coasted to renomination for what is likely to be a new term in November.

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 Obama.