The nomination of Robert H. Bork to the Supreme Court, once viewed by President Reagan as an opportunity to leave a conservative judicial legacy extending into the next century, has instead become an embarrassing advertisement of his diminished political authority and of the unresolved conflicts within his administration.

Even before the Senate Judiciary Committee rejected Bork on Tuesday, competing factions within the administration blamed each other for the defeat. Conservatives who look to Attorney General Edwin Meese III complained that political pragmatists led by White House chief of staff Howard H. Baker Jr. had botched Bork's case by presenting him as a mainstream moderate. Baker's defenders replied that the conservative strategy of presenting Bork as an ideological activist would have meant an even more resounding defeat.

But neither side of the debate was blaming the man who, in the opinion of some senators, arguably cost Bork his chances long before he was nominated. The real loser and the man who created the political challenge in the first place was Reagan, who insisted on trying to "nationalize" the 1986 midterm election and make its outcome a test of his policies and judicial appointments.

"The president doesn't have the clout with southern Democrats he had in 1981," Sen. Richard C. Shelby (D-Ala.) observed yesterday. "He hadn't campaigned against all of us back then. Now, we have to look beyond the president to our own constituents and our own futures."

Shelby should know. He was one of the Democratic candidates Reagan targeted to campaign against in 1986, when the Republicans lost eight Senate seats and control of the Senate. In speech after speech Reagan made his judicial philosophy a litmus test of the election and said -- as he did at an Oct. 8, 1986, rally for then-Rep. James T. Broyhill (R-N.C.) -- that the proliferation of drugs and the "crime epidemic" can be traced to "liberal judges who are unwilling to get tough with the criminal elements in this society."

"We don't a need a bunch of sociology majors on the bench," Reagan said. "What we need are strong judges who will aggressively use their authority to protect our families, communities and our way of life . . . judges who do not hesitate to put criminals where they belong -- behind bars. And since coming to Washington, we've been putting just such people on the bench."

Broyhill lost his bid for the Senate to Terry Sanford, who last week became one of the first southern senators to declare opposition to Bork. So did senators from Texas, Alabama and South Carolina, all states in which Reagan had given speeches denouncing judicial permissiveness and attacking by name the two Democratic senators, Edward M. Kennedy (Mass.) and Judiciary Committee Chairman Joseph R. Biden Jr. (Del.), who led the fight against Bork's confirmation.

Speaking in Columbus, Ga., last Oct. 28, Reagan extolled Sen. Mack Mattingly (R-Ga.) as a man who "can make all the difference" on judicial appointments. "Without him and the Republican majority in the Senate, we'll find liberals like Joe Biden and a certain fellow from Massachusetts deciding who our judges are." Mattingly also lost.

From the time Bork was nominated early in July the public battle over the nomination was accompanied by an internal administration struggle. Baker and White House deputy chief of staff Kenneth M. Duberstein recognized that Reagan had lost much of his southern base and had to stress Bork's undisputed legal credentials and personal integrity to have any chance at all. This strategy prevailed, but conservatives complained constantly that the White House was presenting an inaccurate and unconvincing picture of Bork.

One official who said that the consequences of the conflict produced a "muddled strategy" that confused voters and some senators. "We seemed to be making different arguments at different times," the official said.

The conflict between the factions, a regular and damaging feature of the Reagan presidency, has left some hard feelings in its wake. On Tuesday, just before the Judiciary Committee convened, veteran lobbyist Tom C. Korologos, who had been brought in by the White House staff to manage the Bork nomination fight, was standing near the press section surrounded by reporters.

Off to the side stood Assistant Attorney General John R. Bolton, the chief Justice Department lobbyist during the hearings. When a reporter mentioned to Bolton that Korologos was surrounded by journalists, Bolton replied with a trace of bitterness, "He should be, it's his strategy."

A case could be made, however, that in a larger sense the strategy was President Reagan's. He took his case and his arguments to the American people and in the 1986 elections he insisted on making a test of his presidency. Like Bork, Reagan lost.Staff writers Edward Walsh and Dale Russakoff contributed to this report.