Sen. John Kerry (search), who had hoped to be center stage Thursday, watched somberly from a seat far across the platform as President Bush (search) took the oath of office, but he sounded a note of defiance as he looked ahead to the next four years.

"Democracy means working together for the good of our country; it also means keeping faith with your ideals, never retreating from core convictions even as you work to find common ground," the four-term Massachusetts Democrat said in a statement.

"We have strong differences and we argue and fight with all our hearts and energy, and our system endures because we Americans expect nothing less," said Kerry, who narrowly lost his bid for the White House.

On a day of celebration for Republicans, Rep. Jim McDermott, D-Wash., took aim at the president and his party during a "counterinaugural ball" hosted by the liberal Americans for Democratic Action (search).

"I don't deny President Bush his right to an inauguration," said McDermott, who is the group's president. "But you can't have it both ways. A costly war in Iraq and a party to excess at home seem to me to be just like drinking and driving. They don't mix."

From Kerry, a bit of a shrug was the response when he was, as Bush took the oath of office, how he was doing. The senator and his wife, Teresa Heinz Kerry, chatted with others on the inaugural platform, and he later attended the congressional luncheon.

Rather than attend inaugural balls in the evening, Kerry gathered close family and friends at his Georgetown home for dinner.

While civility was the public demeanor at the inauguration, many Democrats made it clear that once the president's big day was over, the battle will begin anew.

Senate Democratic leader Harry Reid of Nevada said he is hoping that the partisan rancor and squabbling of the past four years will give way to a more cooperative tone. "I am optimistic and confident today can be a new beginning, but it can only be a new beginning if that tone will carry forward," he said.

House Democratic leader Nancy Pelosi of California and Sen. Charles Schumer, D-N.Y., used the inaugural as a fund-raising tool.

Schumer, chairman of the Democratic Senatorial Campaign Committee, told supporters in a fund-raising e-mail that "when the inauguration bands stop playing and Congress comes back into session, we Democrats will be on guard and ready to fight against the Republicans' extreme policies once again."

Pelosi said, "Personally, I don't feel much like celebrating. So I'm going to mark the occasion by pledging to do everything in my power to fight the extremist Republican's destructive agenda."

In a similar e-mail to Democratic supporters, she sought donations to the Democratic Congressional Campaign Committee, to "tell President Bush that party time is over."