The big spending shifter from Arizona fools them one more time

John McCain holds a comfortable lead in the contentious Arizona Republican Senate primary, according to the most recent public polling, making him the strong favorite against former Rep. J.D. Hayworth on Tuesday.

But it’s been a costly road to a 5th term for the 2008 GOP presidential nominee, and the experience is likely to leave a lasting and unsightly stain on his legacy.

It’s not just the $20 million he’s spent already this election or the scorched earth campaign that he’s run. Rather, it’s the choices he’s made and the positions he’s embraced—and what it reveals about him—that could make for a complicated final chapter in his political biography.

Once the sponsor of comprehensive immigration reform with the late Sen. Ted Kennedy—a stance that hurt him with conservatives—McCain moved in a different direction this year. He switched his emphasis this summer to border security, embraced the Arizona’s controversial hardline immigration law and, in an ad, called on the federal government to “complete the danged fence”—three years after dismissing the notion of a border fence in a Vanity Fair article headlined, “Prisoner of Conscience.”

Four years ago, McCain also told students he supported repeal of the “don’t ask, don’t tell” policy that bans gays from serving openly in the military. But in May, the former war hero and Navy POW promised to filibuster any bill including that change that landed on the Senate floor.

He sidestepped the climate change debate this year despite once being a Senate leader on the issue and he’s even distanced himself from the term that once seemed central to his political brand—his “maverick” trademark.

Hayworth, the primary election opponent McCain has spent a small fortune pummeling as inept, corrupt and even stupid, has seized on the apparent contradictions.

“Mr. campaign finance reform . . . the guy who used to lecture us about the evils of money . . . thinks he’s going to buy off Arizona,” Hayworth told POLITICO. “Maybe it’ll work. Hey, they spent $20 million.”

Former advisers to McCain, who declined an interview for this story through a spokesman, were wary of publicly offering their thoughts on how this smashmouth primary campaign—potentially the last for the 73-year–old senator—has changed the former captain of the “Straight Talk Express.”

It’s widely assumed McCain’s move to the right is rooted in political expediency—the Arizona Republican primary electorate is conservative and to win renomination, McCain needed to convince those voters of his bona fides.

While McCain heads into Tuesday’s contest holding a steady double-digit polling advantage, his supporters are quick to point out that there was a time this race was not a slam dunk.

In November 2009, a Rasmussen Reports survey showed the four-term senator clinging to just a two-percentage-point lead over Hayworth, who had not even yet entered the race. In that same survey, 61 percent of Arizona Republicans said they felt McCain had lost touch with those in his own party. Even five months later in April, just a third of primary voters viewed McCain “very favorably,” while a staggering 85 percent said gaining control of the border was more important than legalizing the status of immigrants here illegally.