PROVIDENCE — Lincoln D. Chafee began thinking about leaving the Republican Party in 2004, when he saw the November election returns from Ohio showing President Bush winning a second term.

The U.S. senator, in the seat his family had held for three decades, said he could see what would come next. With Mr. Bush’s reelection, the war in Iraq would continue. The support for the war, and the president, would plummet. And last year, when Chafee and other Republicans in Congress came up for reelection, that wave of unpopularity was going to wash them out.

“I could see it as clear as day,” Chafee said yesterday.

Chafee had already distanced himself from the Republican Party and President Bush. He was the only Senate Republican to oppose the resolution supporting the invasion of Iraq. He bucked his party on environmental, social and tax issues — coming down on moderate principles instead of conservative party line.

But the decision he made in July to disaffiliate from the Republican Party wasn’t one he wanted to make while in office, he said. To give up his affiliation while in the Republican-controlled Senate, with a Republican president, would have meant giving up Rhode Island’s political clout.

While on the Environment and Public Works Committee, Chafee negotiated a financing formula in gas taxes that gave Rhode Island the second-highest return, just behind Alaska. During the base realignment and closure in 2005, Rhode Island added 500 military jobs, while other states lost, Chafee said. Without his Republican affiliation, “it’s safe to say Rhode Island would not do well,” Chafee said. “There would have been retribution.”

After he lost the November election to Democrat Sheldon Whitehouse, Chafee talked about leaving the Republican Party. Now, he is just Lincoln Chafee, private citizen. He said he isn’t interested in becoming a Democrat. “The Democratic Party is just as bad,” Chafee said. “It’s leaderless and complicit in this war. The national Democratic Party has no attraction to me, absolutely.”

Reaction to his disaffiliation has varied — from dismay, to support, to shrugs of “it’s about time.” Everything, it seems, but surprise.

“The former senator is personally well-liked, well-regarded, and he always will be, but it is no surprise that having had a long difficult struggle as a moderate with the more conservative wing of the party in Washington, he felt estranged by the party,” Rhode Island GOP Chairman Giovanni Cicione said in a statement. Warwick Mayor Scott Avedisian, who called Chafee his “political soul mate,” was also unsurprised. Avedisian had worked for Chafee’s father, the late Sen. John Chafee, and then with Lincoln Chafee in Warwick city politics, when Chafee was the mayor and Avedisian was on the City Council. “I’m saddened to see him go,” Avedisian said. “When you look at the only two Republican senators [from Rhode Island] to be John Chafee and Linc Chafee, it’s one more step away from Rockefeller.”

The “Rockefeller Republicans” are a nod to the past — the GOP New York Gov. Nelson Rockefeller and vice president under President Gerald Ford, who stood for moderate views on domestic and social issues. This was the philosophy of the Chafee family, but not the current Republican Party. “I can’t say I blame him,” said Democratic State Chairman William Lynch. “There’s no question the Republican Party has been hijacked by the conservative right wing.”

“I’d always expected him to leave the Republican Party, and I didn’t understand — why did they spend so much time and effort on someone who was going to let them down?” said former Cranston Mayor Stephen Laffey , who ran against Chafee in last year’s Republican primary. “I wish that he’d been honest with himself, the voters, his constituents and especially the people who gave him money for his campaign.”

Republican National Committeewoman Eileen Slocum, of Newport, said she wasn’t surprised Chafee left — “he was tending toward liberal principles” — but says he will regret it. She believed Chafee’s refusal to support the president cost him reelection. “[The president] expected to win, and we will win,” Slocum said.

The reaction around Brown University, where Chafee is a distinguished visiting Fellow at the Thomas J. Watson Jr. Institute for International Studies, has been supportive, as has reaction from other areas, he said. He pointed to Cumberland Rep. Richard W. Singleton, who recently disaffiliated from the Republican Party out of disgust with the president’s handling of the Iraq war and Republican lawmakers in Washington. “There’s a feeling of alienation from the party,” Chafee said.

Rumors in political circles have Chafee running for office in 2010 as mayor of Providence, governor or general treasurer. He coyly hinted as much two days after losing the November election, when he joked about running for mayor since he and his family had moved to the East Side. Brown political science Prof. Darrell West said yesterday that several months ago Chafee told him he loved being mayor of Warwick and mentioned running for mayor of Providence. “A mayor’s job is very concrete and practical, and you really affect people’s existence,” West said. Unlike in Washington, where the politics are partisan and “nothing gets done.”

So, Providence mayor in 2010?

“I wouldn’t lend any momentum to that,” Chafee responded.

amilkovi@projo.com