GRAND RAPIDS, Mich. — Republicans Mitt Romney, son of a Michigan governor, and Sam Brownback promoted their presidential campaigns yesterday before nearly 3,000 party activists at their state convention.

The delegates listened enthusiastically to speeches by Romney and Kansas Sen. Brownback, as well as the surrogates speaking for Arizona Sen. John McCain and former New York City Mayor Rudolph Giuliani.

GOP Chairman Saul Anuzis tried to dampen competition between the candidates’ supporters after he was reelected to a second two-year term.

“I’m asking you to get involved, fight the fight,” he said, then warned: “Get along with one another.”

Michigan is crucial for Romney, who hopes to build on his ties to his native state, where his father, George, was governor from 1963-69.

McCain is hoping for a second surge of the popularity that propelled him to a 2000 win over then-Texas Gov. George W. Bush in the Michigan GOP primary.

Romney reminded the crowd that he grew up sharing the Automotive News each morning with his dad, who headed American Motors Corp. before he became governor. He said his father brought many of the lessons he learned from business to the governorship.

“He got Michigan moving again,” Romney said, before running through his stands opposing abortion, favoring the restriction of marriage to a man and a woman and backing controls on illegal immigration. “It’s time for Republican principles to come back to Michigan again.”

Brownback, who is running as the conservative heart of the party but opposes President Bush’s decision to send 21,000 more troops to Iraq, got a warm reception with his pledges to protect life and the traditional family.

He also called for wiping out cancer in 10 years and for putting more resources into alternative energy.

“Michigan is going to be a key state in getting that done,” he said, noting its efforts to encourage the production of ethanol and biodiesel.