As his fellow incumbents drown in a tea-party wave, Sen. John McCain somehow remains afloat. On Tuesday, McCain squared off against J. D. Hayworth, a former congressman, in Arizona’s GOP Senate primary; yet Hayworth, a border hawk and talk-radio star, arrived defanged. After lurching hard, and awkwardly, to the right for months, McCain won easily. McCain of course credits his survival to pluck. But luck, too, played a part, as did his boatload of cash. Unlike many of his colleagues, who have faced political neophytes this season, McCain drew a foe with twelve years of experience in the House — a short stint compared with McCain’s nonstop congressional tenure since 1983, but more than enough of a record for opposition researchers to mine. McCain, with ease, punched early: Hayworth was a well-known pork-barrel spender and an acquaintance of Jack Abramoff, the disgraced lobbyist. Initially, “Hayworth tried to portray himself as an outsider, as some sort of fiscal conservative,” McCain told me before the primary. “We knew that we had to define him — I freely admit that.”

“We did not want to make the mistakes of Charlie Crist and Bob Bennett and become another statistic,” adds Brian Rogers, McCain’s communications director, referring to a pair of establishment candidates who found themselves in trouble. “Look at what happened to Crist,” he says. In Florida’s GOP Senate primary race, Governor Crist ignored Marco Rubio, his upstart opponent, “for months, enabling him to shape the narrative.” With Hayworth, “we simply could not let that happen. Bold colors were necessary.”

But the senator’s own baggage weighed heavily on him. On immigration, McCain was understandably viewed with suspicion. Along with Ted Kennedy, he had co-sponsored, in 2007, a “comprehensive reform” bill that many critics saw as a veiled move toward amnesty. Beyond that, there was a never-ending scroll of past dalliances with Democrats. So Hayworth, too, came armed. For the first few months of the campaign, he hammered McCain for his votes against the Bush tax cuts and for the bank bailout, to the delight of voters frustrated with Washington. As winter turned into spring, Hayworth’s poll numbers began to tick up, from 22 points down in Rasmussen’s January survey to just seven by mid-March. The former drive-time host on KFYI, charismatic and with a linebacker’s build, basked in the attention. He was going to be a giant-killer, the Great Right Hope.

When I found Hayworth greeting his fans at the Conservative Political Action Conference in late February, the candidate was boastful. “John McCain is vulnerable on everything,” he said, beaming. “He should rename his bus the Double-Talk Express. His campaign of conservative conversion is just sad and predictable.” Yet all was not well in Hayworth land: A clip from his talk show in which he chatted about President Obama’s birth certificate surfaced, and McCain pounced. “Consumed by conspiracies!” screamed one spot. Instead of being able to highlight McCain’s policy shifts, Hayworth was boxed into a corner, forced to deny, over and over again, that he was a “birther.” Then, while at CPAC, he caught more flak, this time for sitting down for an interview with the John Birch Society.