PHOENIX — For Gov. Jan Brewer, the passage last month of a Medicaid expansion was a major coup. Despite a Republican majority in the Legislature, where she faced significant opposition from Tea Party members, she rallied the entire Democratic delegation to her side and made a progressive issue palatable to just enough conservatives, casting the expansion as the right decision for the state, morally and monetarily.

“It’s pro-life, it’s saving lives, it is creating jobs, it is saving hospitals,” Ms. Brewer said in an interview from her office in the Capitol’s executive tower, where she conducts what she often describes as “the people’s business.”

“I don’t know how you can get any more conservative than that,” she said.

A lot of conservatives disagree. Ms. Brewer’s maneuvering, including a threat to veto any bill brought before her until the expansion was voted on and a last-minute call for a legislative special session to force the vote, has sparked ire among the Republican rank and file. In interviews, many of its most loyal members conceded that the party’s once cohesive ideology has been tainted by the governor’s stance, and they are arming themselves for payback.

Name-calling, once reserved for closed-door encounters and precinct committee meetings, has seeped into the public debate, loudly. One conservative blog, Sonoran Alliance, has taken to describing the Republican legislators who voted for the expansion as “Brewercrats” and the expansion itself as “Obrewercare,” a play on the Republican moniker for President Obama’s health care overhaul.