As an investigator for California Democrat Henry A. Waxman’s Oversight and Government Reform Committee in the House, Phil Schiliro has been in the middle of high-profile confrontations with the White House over sensitive documents and testimony from hostile witnesses such as Karl Rove. Now Schiliro has taken on a lower-key job: the Barack Obama campaign’s liaison to Democrats in Congress.

His role is to keep peace, and maybe even harmony, between the Obama organization and dozens of lawmakers who have their own issues and re-election campaigns to worry about. Democrats this year have “an extraordinary interest in unity,” Schiliro says. “Experience has given me an appreciation of the unique demands on both Congress and political campaigns.”

Obama had hardly locked up the presidential nomination last month before Democrats on the Hill were showing signs of annoyance that they weren’t being briefed and consulted more by his campaign. Republican John McCain, who had more time to attend to such things, has had a liaison in place since April: John Green, a longtime Senate aide to Trent Lott who’s now on leave from his position as managing director of Ogilvy Government Relations.

Schiliro, 51, has been trying to broaden communications between lawmakers and Obama and his campaign. Waxman says his longtime aide is perfectly suited to his new job as a troubleshooter from his days in the House and as policy director to Tom Daschle when the South Dakotan was Senate minority leader. “He’s a born diplomat,” Waxman said.

The top Republican on Waxman’s committee, Virginia’s Thomas M. Davis III, described Schiliro as a formidable but respected adversary. “It’s too bad the Bush White House hasn’t had someone like him in that type of job,” Davis said. “He’s honest. He’s very pro-active. He will talk to members, take notes and get back to them.”

Schiliro first went to work for Waxman in 1982 and twice ran for the Long Island House seat now held by Democrat Carolyn McCarthy. “He barely missed being a member himself,” noted Davis.