Clinton was the only major Democratic candidate whose name appeared on the ballot, and lack of voter interest hobbled a push by supporters of Sen. Barack Obama of Illinois and former Sen. John Edwards of North Carolina to try to embarrass her with a strong showing for "uncommitted."
Clinton prevailed with 55% in a race in which only three active candidates' names appeared -- hers, Rep. Dennis J. Kucinich of Ohio and former Sen. Mike Gravel of Alaska. Sen. Christopher J. Dodd of Connecticut was also on the ballot, even though he has withdrawn from the race.
"Uncommitted" picked up 40% of the vote.
Some analysts had set a 60% threshold for Clinton to avoid the embarrassment of seeming to face a stiff challenge from an "anyone else" vote, but Bill Ballenger, a veteran Lansing, Mich., political analyst, said Tuesday's result was "probably good enough."
"I don't think she's going to be holding any major press conferences to extol her victory," he said.
Obama and Edwards withdrew their names in October after the Democratic National Committee penalized Michigan for scheduling its primary ahead of the approved Feb. 5 date. Some Democrats felt compelled to vote anyway, even though Michigan's delegates have been barred from playing a role at the convention.
"I just wanted my voice to be heard," Obama supporter Neftali Ramos-Ortiz, 19, said after casting his vote for "uncommitted" in Pontiac Central High School's gym, near the heart of the economically battered city.
Though the vote was meaningless, Obama and Clinton traded memos over the races here and in Florida, which also has been sanctioned for scheduling its primary for Jan. 29. All the major candidates had pledged to not campaign in either state.
Michigan party officials have said they expect the state will have its convention seats restored, and they plan to allocate the uncommitted delegates at party meetings, open to all Democrats, in March.