WASHINGTON - Thousands of conservative activists converged on Capitol Hill for a rally yesterday, a last-ditch effort to kill the Democrats' health-care legislation they called "Pelosi Care."

The protesters converged on the west lawn of the Capitol waving flags, ringing cowbells, and chanting, "Kill this bill." Many carried signs, including, "Waterboard Congress" and "No Socialistic Health Care."

Dozens of Republican lawmakers, led by Rep. Michele Bachmann of Minnesota, stood on the Capitol steps and pledged to do all they could to defeat the health-care bill by tomorrow, when House members plan to vote.

"You came! You came to your House!" said Bachmann, who organized the "Hands Off Our Health Care!" rally with impassioned pleas in recent days on conservative talk radio and cable television shows.

Many of the protesters are members of local "tea party" movements. Democrats cast them as an "extreme tea-party crowd."

"If the Republican Party wants to make Michele Bachmann the voice of the party, that's more than fine with us," Democratic National Committee spokesman Hari Sevugan said in a statement.

"It's their extreme right-wing, rigid ideological agenda that has Americans leaving the Republican Party in droves - and so, if displays like today are what they think is a smart political strategy, all we can say is: Go for it."

After the rally, Capitol Police arrested a dozen antiabortion activists on disorderly-conduct and related charges outside an office belonging to House Speaker Nancy Pelosi (D., Calif.) in the Cannon House Office Building. It was not clear whether this group had come from the tea-party protest.

Hours before the rally began, Capitol Police arrested nine pro-overhaul activists in the Hart Senate Office Building and charged them with unlawful entry.

They had staged a sit-in the seventh-floor office of Sen. Joseph I. Lieberman (I., Conn.), demanding that he return campaign contributions from health insurers. Lieberman has threatened to join Republicans in a filibuster against the bill.

Outside the Capitol, a parade of GOP lawmakers used fiery rhetoric to try to build momentum on their party's electoral victories Tuesday and stop health-care legislation, President Obama's top domestic priority.

Rep. Mike Pence of Indiana, chairman of the Republican Caucus, said the bill was "a freight train of government spending" and said the demonstrators were delivering a message to Pelosi:

"Madam Speaker: We the people are tired of runaway spending in Washington, D.C., and we the people want health reform that lowers the cost of health care, not grows the size of the federal government," Pence said.

Conservative activists, some of whom traveled far to come to Washington, seemed moved by the speeches.

Scott Krafft, 51, an investment consultant from Fort Wayne, Ind., drove 10 hours overnight with his wife and three children to attend. He said he was inspired to attend by listening to Bachmann on Sean Hannity's radio show.

"We want to keep capitalism and individual responsibility at the center of our society," Krafft said.