Cruz argues that there's nothing unusual about his making nice with former foes. "Typically, after a primary, one hopes to see Republicans unite," he said in an interview. "That's what's supposed to happen."
Still, Cruz became a national symbol of tea party might when he upset Lt. Gov. David Dewhurst, a 14-year veteran of Texas politics endorsed by Gov. Rick Perry and much of the state GOP mainstream.
The lieutenant governor won the Texas primary in May by 10 percentage points, but failed to capture a majority in a nine-Republican field. Cruz then painted Dewhurst as a closet moderate beholden to the party establishment and whipped him by nearly 14 points in a July runoff.
Cruz's new opponent, former Democratic state Rep. Paul Sadler, says Cruz is a political novice who is too extreme for even a state as conservative as Texas -- where no Democrat has won statewide elected office in nearly 20 years.
But Cruz responded that Sadler's 12 years in the Texas House ended in 2003, adding: "I don't agree with him that the only people that deserve a public office are those who have held elected office for many, many years."
Cruz continues to campaign across Texas, striking a decidedly populist tone while pledging to reign in federal spending and get "government's boot off the necks of small businesses."
But Cruz has also appeared at fundraisers lately with both Dewhurst and Perry. He's similarly raised money with the woman he's vying to replace, retiring U.S. Sen. Kay Bailey Hutchison, U.S. Sen. John Cornyn and Texas Attorney General Greg Abbott. And all this comes after Cruz spoke at the Republican National Convention.
Asked if he's still an insurgent, Cruz said, "Sure I am."
"We just came through a $50 million primary, the most expensive primary in the country," he said, "and we were outspent 3 to 1."
Indeed, GOP strategist Matt Mackowiak said Cruz has to replenish his campaign coffers since his primary contributions can't be spent campaigning for the Nov. 6 general election -- and party veterans have a broader donor base than a relative newcomer like Cruz.
"Once you get through a primary, everybody's establishment," Mackowiak said.
Cruz was a virtual unknown when he mulled a run for attorney general in 2010 but chose not to challenge Abbott. Instead, he announced he would campaign for U.S. Senate -- defying Dewhurst, who has overseen the powerful Texas Senate since 2003.
The owner of an energy company, Dewhurst spent $20 million of his own money on the campaign. Cruz countered with large donations from national tea party groups. The Washington-based, free-market advocacy organization Club for Growth spent $5.5 million supporting Cruz -- but says it doesn't feel gipped now that he's mending Republican fences.
"Grassroots conservatives don't care about words, they care about actions. Ted Cruz has changed neither," said club spokesman Barney Keller. "He will vote to limit government and to increase economic liberty when he's in the Senate. I don't think anyone has any doubt about that and his rhetoric hasn't changed."
Julie Turner, president of the Texas Patriots PAC in suburban Houston, said of Cruz, "He does have to represent all of Texas now, so we want him to work with other people but still stay principled."
"It's not Cruz becoming establishment," Turner said. "It's Dewhurst and others becoming friendlier to him."
A former Ivy League debating champion with degrees from Princeton and Harvard, Cruz wouldn't appear to cut much of anti-establishment figure. He even fell in love with his wife Heidi while both were working on the 2000 presidential campaign of George W. Bush -- now often a target of tea party ire for running up large federal deficits.
Cruz argued cases on behalf of Texas as the state's solicitor general between 2003 and 2008 but he was appointed by Abbott, meaning he's never held political office.
The son of a Cuban-American who fled the island before Fidel Castro took power, Cruz was born while his parents were in Alberta during a Canadian energy boom, though he grew up mostly in Houston.
That likely makes Cruz eligible for dual U.S.-Canadian citizenship -- ironic given that his native country has a nationalized health care system and Cruz has been a fierce critic of the Obama administration's health care overhaul.
"I am a U.S. citizen," Cruz said. "I have only ever had one passport and that is a U.S. passport." He refused to elaborate, and Canadian consular officials won't comment, citing privacy concerns.
"I was born in Calgary," Cruz quipped, borrowing an old line from Bush, "because I wanted to be near my mother at the time."