Massachusetts Senator John Kerry has won Democratic Party caucuses in Michigan and Washington State by a wide margin.
With more than 90 percent of precincts reporting, Senator Kerry had won a decisive 50 percent of the vote in Michigan, far ahead of former Vermont governor Howard Dean, who trailed at 17 percent.
Mr. Kerry also won nearly 50 percent of the vote in Washington State, with four out of five of precincts reporting. Mr. Dean also came in second there, at 30 percent.
The two wins give Mr. Kerry nine victories in the 11 Democratic primaries and caucuses held so far. He became the frontrunner last month after winning contests in Iowa and New Hampshire.
Speaking Saturday in Virginia, ahead of Tuesday's primary there, the Massachusetts senator looked ahead to the general election as he called President Bush and his advisers "extreme." Mr. Kerry is anticipating Republican criticism that his positions are too liberal. He says he and his fellow Democrats represent the American mainstream.
"I have news this time for George Bush and Karl Rove and Ed Gillespie and the rest for their friends," he announced. "I am not going to back down. I am one Democrat who knows how to fight back, and I've only just begun to fight."
The northeastern state of Maine will hold caucuses on Sunday, but Mr. Kerry's biggest challenge will be Tuesday's primaries in Virginia and Tennessee.
His leading challengers there are two southern candidates, North Carolina Senator John Edwards and retired general Wesley Clark. Both trailed far behind in Washington and Michigan, but hope for a better showing in the southern states.
Howard Dean, the former Democratic frontrunner, suffered a setback Saturday when a major labor union, the American Federation of State, County and Municipal Employees, withdrew its support. Mr. Dean is pinning his hopes on a win in Wisconsin on February 17.