Texas Democrat-turned-Republican Phil Gramm is expected to recapture his seat in Congress in a special election here Saturday. But a Gramm victory could turn into better news for the Democrats he broke away from than for the Republicans he joined last month.
Political analysts here say Republicans may regret exchanging the advantage of having a friend behind enemy lines for the disadvantage of having a maverick in their own camp.
As a second-term congressman, former economics professor Gramm made his name in the 97th Congress as President Reagan's favorite Democrat. From his hard-won perch on the House Budget Committee, Mr. Gramm rejected Democratic Party proposals. Instead, he steered the two administration-drafted Gramm-Latta budget bills through Congress.
Gramm's reward for two years of feuding with his own party came Jan. 3 when the Democratic leadership dropped him from the House Budget Committee. Gramm responded two days later by giving up his House seat and running for reelection as a Republican.
New Right campaign strategist Richard Viguerie says that ''Phil is going to play a major role nationally.'' He predicts Gramm will help swing the Republican Party away from ''the country-club, elitist types running the White House now'' and toward more ''populist, conservative'' policies.
Boll-weevil Democrats who joined Gramm in voting with the Reagan administration will watch Gramm closely, Mr. Viguerie says.
If Gramm wins with about 65 percent of the vote in his traditionally Democratic Texas Sixth District, say analysts here, some of Congress's 30 to 40 other boll weevils might consider switching parties. But the key factor may be how well Gramm is able to work with his new Republican colleagues.
In terms of political clout, Gramm may be far less effective as a GOP congressman. He has been promised a Republican seat on the House Budget Committee. But if he returns to the committee, this time he will be on the minority side, one of 11 Republicans amid 20 Democrats. And Gramm will no longer be able to deliver firsthand reports on Democratic Party strategy to his close friend, budget director David A. Stockman.
Neeley Lewis, Democratic Party chairman for Brazos County at the center of Gramm's district, describes Gramm as a close friend who is ''extremely bright and articulate and believes strongly in the positions he takes.'' But Mr. Lewis has endorsed Gramm's leading opponent, Dan Kubiak, a former state legislator. Lewis says Gramm's future effectiveness as a congressman is very much in doubt. It depends, he says, on whether Gramm is ''welcomed back into the club'' or ''viewed with disdain and considered untrustworthy'' by fellow congressmen.
University of Houston political scientist Bruce Oppenheimer says Gramm may find life difficult as a Republican. He says Gramm's past ability to sign up Democratic votes for administration bills may be lost because ''Democrats who worked with him in the past probably will not work with him now.''
Texas A & M political scientist David Hill says ''Phil Gramm may simply fade into obscurity after his reelection, because it's newsworthy when a Democrat supports the President, not when just one more conservative Republican lines up with the Reagan administration.''
Mr. Hill, Mr. Oppenheimer, Lewis, and others say they suspect that the $783, 000 Gramm spent last year in the Democratic primary, coupled with this year's self-imposed reelection battle, are part of a plan to gain visibility and capture Republican John Tower's US Senate seat in 1984.