By Coral Davenport, CQ Staff

The day after Barack Obama won a resounding victory in the presidential sweepstakes, Rep. Henry A. Waxman , D-Calif., started making phone calls.

He had decided to harness Obama’s message of change to launch a bold campaign to topple the House’s longest-serving member, John D. Dingell , from his perch atop one of the most powerful committees in Congress. Waxman’s first call went to Dingell.

“I told him what I planned do,” Waxman said. “He did not agree with what I was doing.”

The gamble paid off Thursday, when House Democrats voted 137-122 to unseat Dingell, 82, as chairman of the Energy and Commerce Committee. The 69-year-old Waxman — first elected to the House 34 years ago in the aftermath of Watergate — took a page from Obama’s playbook and cast himself to colleagues as an agent of change.

In a methodical, behind-the-scenes campaign, Waxman called on fellow liberals and Californians, his natural allies, for support. He also called many of the party’s “old bulls” — committee chairmen and senior members who would most likely side with Dingell.

“He talked to me and told me he was running on change,” said Charles B. Rangel , D-N.Y., powerful chairman of the Ways and Means Committee. “I told him, ‘I don’t want change!’”

But Waxman’s message did resonate with many other Democrats, especially younger and newly elected lawmakers, as well as those who want to push an aggressive agenda on environmental and energy issues. Environmentalists have criticized Dingell, an ardent defender of his home state’s auto industry, for moving too slowly on legislation to restrict greenhouse gas emissions.

“Waxman won on ideology and generation,” said Bill Pascrell Jr. , D- N.J., “I think it was basically the freshmen and sophomores who decided this election. They were the force in this. And they should be a force in how we decide things.”

Florida Democrat Debbie Wasserman Schultz , who was just elected to her third term, said Waxman’s appeal struck a chord with younger members inspired by Obama.

“His focus was on change, the fact that we need to move forward aggressively,” she said.

In addition to making that philosophical appeal, Waxman strategically gave financial help to the House campaigns of younger Democrats, using his political action committee to donate as much as two to five times as much as Dingell to individual candidates.

Many of Dingell’s backers said they thought younger members, typically respectful of the institutions of seniority and leadership, would defer to the veteran committee chairman.

Waxman’s challenge initially seemed to catch Dingell off guard, but he fought back with a public campaign designed to demonstrate his support. Dingell rolled out lists of supporters and lined up backing of key constituencies, including members of the moderate Blue Dog Coalition and the House’s caucuses of black and Hispanic lawmakers.