Washington — Controversy over several of President-elect Ronald Reagan's Cabinet nominees is elevating their Senate confirmation into the first real political test of the yet-to-be-inaugurated Republican administration.
It also looms as the political baptism of the Senate's spanking-new Republican majority, which will find itself presiding over the screening of a cabinet after a quarter of a century of presiding over nothing at all on Capitol Hill.
Senate Democrats, smarting over their fall from power in the Reagan election sweep, show signs of eagerly awaiting the confirmation hearings as an opportunity for partisan retribution -- and some of the Cabinet choices may offer them plenty of target.
At least three of the nominees -- Alexander M. Haig Jr. for secretary of state, Donald T. Reagan for secretary of the Treasury, and James G. Watt, reportedly in line for secretary of the interior -- seem in store for more than cursory examination.
"The Senate's work must be thorough," insists Democratic leader Robert C. Byrd of West Virginia, who didn't shrink from challenging a president-elect of his own party over a troublesome cabinet-level appointment four years ago. It ended with Jimmy Carter's nomination of Theodore C. Sorensen to head the Central Intelligence Agency being withdrawn.
The new President-elect has told Senators that he would like all of his Cabinet choices confirmed before he is sworn into office.
But the scant two weeks between the opening of the new Congress Jan. 5 and the inauguration Jan. 20 may offer too little time. The hearings on the Haig nomination, for instance, aren't scheduled to begin until just seven working days before the inauguration.
Like his predecessor, Mr. Reagan may have to start his term with an empty chair or two around the Cabinet table.
No outright rejection of any of his nominees is yet foreseen -- that has happened only eight times in the nation's history -- but tough confirmation battles could inflict early political damage on the infant administration.
The most intense scrutiny is likely to focus on the selection of Mr. Haig, the retired Army general who served in the Nixon White House as deputy to then-National Security Adviser Henry A. Kissinger and later as chief of staff.
Senate Republican leader Howard H. Baker Jr. of Tennessee, who also sits on the Foreign Relations Committee that will screen Haig, concedes he is going to be "a controversial nomination . . . one of the most picked over, looked at, and examined private lives to come before the Senate as a presidential nominee in a long time."
Democrats on the panel are gearing up for a full-scale probe by hiring former Senate Watergate investigator Terry F. Lenzner to look into Haig's role in the Vietnam war, the wiretapping of former government officials and reporters, and President Ford's pardon of Mr. Nixon.
These issues will be aired before a Senate committee whose makeup suggests it may be less sympathetic to Haig than the rest of the newly Republican and more conservative Senate. The Foreign Relations panel is decidedly moderate ideologically, chaired by middle-of-the-roader Charles H. Percy of Illinois, and bolstered by six new members (four Republicans and two Democrats) -- all rated as moderates or liberals.
A different sort of challenge awaits Treasury Secretary-designate Regan.
The Senate Finance Committee is expected to explore his role as chairman of the brokerage firm of Merrill Lynch & Co. Inc. in a tax-avoidance scheme ruled illegal by the Internal Revenue Service, and in questionable handling of Chrysler Corporation stock and New York City bonds over which the company is now being sued.
The interrogation is likely to be led by Republican conservative purists who harbor ideological qualms about his past financial support of some liberal Democratic politicians.
The apparent Reagan choice for interior secretary, Mr. Watt, faces tough questioning from senators of both parties over the efforts by his conservative Colorado Legal Foundation to overturn many federal controls designed to combat pollution and protect the natural environment -- some administered by the Interior Department he would head.