The possible loss of a U.S. Senate seat in Massachusetts has Democrats on edge 3,000 miles away in California, where party activists fear a GOP upset today could trigger a conservative wave and swamp health care reform and the 2010 midterm elections.

"Regardless of the outcome ... this should be a gigantic wake-up call to the Democratic Party - that we're not connecting with the needs, the aspirations and the desires of real people right now," said San Francisco Mayor Gavin Newsom.

With Republican Scott Brown poised to defeat Democrat Martha Coakley in the Massachusetts race to succeed the late Edward Kennedy, Democrats at the annual Martin Luther King community breakfast in San Francisco were buzzing about the impacts of such an upset: an end to the party's 60-vote supermajority and a possible mortal blow to the health care legislation championed by President Obama.

Ripple effects

But Democrats also considered the ripple effects on coming elections in the nation's most populous state.

"We better get our act together - and quickly," Newsom said. Voters "are so angry. They don't feel that we're paying attention to their needs, in terms of their jobs, and what's going on at the grassroots, in their neighborhoods."

With just 10 months until the 2010 midterm election, the mayor's remarks underscore how the Brown-Coakley race has set off alarms in Democratic-leaning California, which is holding two high-profile elections this cycle.

Sen. Barbara Boxer, a three-term Democrat, faces a re-election challenge - with three Republicans vying to defeat her: former Rep. Tom Campbell, former Hewlett-Packard CEO Carly Fiorina and Assemblyman Chuck DeVore of Irvine.

Boxer polled no more than 46 percent of the vote against any of the three in a Rasmussen Poll released Friday.

And with GOP Gov. Arnold Schwarzenegger termed out, former two-term Democratic Gov. Jerry Brown will face one of two wealthy GOP challengers: former eBay CEO Meg Whitman or state Insurance Commissioner Steve Poizner.

Worse than a canary

For Boxer, a favorite Republican target, a GOP win in Massachusetts would be a particularly dark sign representing "not just the canary in the coal mine," said Wade Randlett, a leading Silicon Valley fundraiser for Obama. "It's the flock of dead ravens landing on the lawn."

But Democratic House Speaker Nancy Pelosi, speaking to reporters Monday, expressed confidence in Boxer - and in Democrats' prospects in California. She insisted that - whatever the outcome - the results today will in no way represent a repudiation of the Obama administration, especially on the matter of health care reform.

"Certainly the dynamics will change depending on what happens in Massachusetts," she said. "But it doesn't mean we won't have a health care bill."

Still, "if Brown wins, then Tea Party supporters will smell blood in California," said Joe Wierzbicki, coordinator of the Tea Party Express, a conservative organization that counts roughly a quarter of its 353,000 supporters in California.

"This would be a sign that the momentum in general is in the direction of the Tea Party movement," he said.

Key differences

There are, however, key differences in party demographics in the two states. While Massachusetts Democrats hold a 3-to-1 registration lead over Republicans, more than half of that state's voters are registered independent.

In California, 45 percent of registered voters are Democrats, 31 percent Republicans, and 20 percent decline to state.

Boxer, unlike Coakley, has run three Senate races - and her office said Monday that she had raised more money than ever in the fundraising period that ended in December. (The figures are to be released today.)

"What happens in Massachusetts in January doesn't predict what is going to happen in California in November," said Boxer campaign manager Rose Kapolczynski. "We're taking nothing for granted."

But "if Brown manages to win, I certainly think that will encourage the supporters" of DeVore, the more conservative GOP Senate candidate, Kapolczynski said. "If the national Tea Party movement engaged ... that could dramatically change the Republican primary."

Going forward, Pelosi said Democrats will continue to pound "Main Street" issues, while Republicans will continue to represent the insurance companies, the wealthy and Wall Street.

American voters will be reminded "the Republicans in Congress ... weren't for Social Security, they weren't for Medicare," she said.

But Newsom said the Republican resurgence in Massachusetts suggests "there's real intensity and fervor out there, as represented by the Tea Party" activists expressing anger at government spending and at job losses.

"This is real," he said. "At our own peril, we dismiss these tea parties as ... some sort of isolated extremism. ... It's not."