When James M. (Big Jim) Thomson of Alexandria stalked the State Capitol through the mid-1970s, he was known as a fierce and partisan Democratic House majority leader, relishing nothing more than a battle, usually with the governor or state Senate.

And at a time when the Washington suburbs were largely a political backwater, the gruff-spoken Thomson was a fulcrum of power, with 22 years of seniority in the tradition-bound legislature certain to make him chairman of the influential House Appropriations Committee, and almost certainly the next speaker.

Then, in 1977, it all came crashing down with his defeat in a bitter election that turned on his unstinting opposition to the Equal Rights Amendment and an unrepentant history of resisting desegregation.

"No question his loss was a setback for Northern Virginia," said current Majority Leader Thomas W. Moss Jr. of Norfolk, himself a late convert to the ERA. Opposition to Thomson was so intense that his opponents successfully fought an effort in 1977 to name him to a state judgeship in Alexandria, an appointment that most former Democratic legislators would have regarded as automatic.

Now, seven years later, and after three years in relative obscurity as Virginia insurance commissioner, Big Jim is back in the thick of things.

This time around, Thomson, who now lives in Richmond, is up for a coveted seat on the powerful State Corporation Commission, the quasi-judicial body that regulates business in Virginia. The seat is a legislative appointment Thomson has sought with four others for the past six months.

But, in a morass of parliamentary maneuvering that no one more than Thomson would appreciate, his nomination to the $64,000-a-year job has become mired in a House-Senate squabble.

Some say Democratic senators apparently are seeking to settle old scores with Thomson by delaying the appointment.

"I don't know the motive of the Senate," deadpanned Moss, who is supporting Thomson, "but I can tell you I'm sure there are many senators over there who remember him."

In many ways, it is a classic Virginia tale of public policy decisions that are determined by years-old personality politics. That, his critics say, was something at which Thomson could excel, remembering every slight and nourishing every defeat for an eventual payback.

In the Senate, Democrats, also spurred in part by power struggles not connected to Thomson, are refusing to acknowledge Thomson's victory in a joint Democratic caucus last week. The House, which favors Thomson, is refusing to vote on the issue again saying the Senate is in error.

Thomson led the joint House and Senate Democratic caucus vote last week, scoring 47 votes to 45 for another former delegate, Edward E. Lane of Richmond. He won the support of most Democrats in the Senate but trailed Thomson among House Democrats.

It may take a ruling by the state attorney general to straighten out the mess. Meanwhile, the 60-year-old Thomson has again become a familiar figure perched in the hallway corners, engaging in lobbying with his friends and by his presence reminding his enemies of his controversial reign.

"Has he renounced his past views?" snapped Judy Goldberg, associate director of the Virginia chapter of the American Civil Liberties Union who sided against Thomson on ERA and condemns his old attempts to discredit civil rights groups, including lawyers for the NAACP.

Thomson, first elected to the House in 1956, is the brother-in-law of former U.S. senator Harry F. Byrd Jr. and was a key supporter of Byrd's father whose poltical machine ran Virginia for several decades and orchestrated the state's ill-fated "massive resistance" to school desegregation.

"He was a real . . . ," one lobbyist began, his sentence trailing off into a grimace.

Thomson, who was nicknamed "landslide Jim" because he won some of his many re-elections by small margins, increasingly fell out of step with the changing Alexandria electorate and refused to change his view on the ERA and other issues.

But many who used to oppose him are strongly supporting his appointment, arguing that those days, as State Sen. Clive L. DuVal of Fairfax said, are largely "ancient history."

Democratic Dels. Mary Marshall of Arlington and Marian Van Landingham of Alexandria say they are more interested in his proconsumer views than his past legislative positions they opposed.

DuVal, chairman of the Northern Virginia Caucus, argues that Thomson's intellect and proconsumer views are needed on the commission, the most powerful regulatory state body in the country.

Thomson himself, rarely comfortable with the media, declines to be interviewed, suggesting he does not want to upset his nomination chances.

But while Thomson wasn't talking, he was the talk of the Capitol.

"Zing them if you could" was Thomson's motto, recalled Moss, enjoying memories of how Thomson could infuriate his opposition and turn it to his advantage. "He was a clever parliamentarian. The only thing he understood was you had to deal with them the Senate in a tough manner," Moss said.

"He was smart, shrewd, honest," agreed Republican State Sen. Wiley F. Mitchell, of Alexandria. And "he was not afraid to use power."

Now, Thomson's many supporters and detractors are waiting to see if he'll get the chance to wield some of that power again.