The party warhorses and the old intellectuals, the men who fought the good fight with Hubert and Orville and Gene and Walter, were in shock in Minnesota yesterday.

The Democrat-Farmer-Labor Party, a fountain of liberalism in modern American politics, the party that produced two Democratic vice presidents in a dozen years, Had been devasted at the polls.

"An era has ended. The Hubert Humphrey era has come to an end," said Dr. Theodore Mitau, one of the state's most respected political scientists and the former chancellor of its university system. "This is part of a broader wave of anger, a frustration at inflation and high taxes, which is sweeping the country. "It's a transition period in American politics."

A case could be made to bolster that argument. Only 10 months after the death of Sen. Hubert Humphrey, long the DFL's titular head, it had lost two seats in the Senate, the governorship and 32 seats in the state legislature.

"For liberals, there was always Minnesota and Massachusetts," said Arthur Naftalin, a former Minneapolis mayor and longtime Humphrey ally. "Now there's only Massachusetts, and we're not too sure about it."

But it's dangerous to read too much into the tribulations of the DFL, or leap to broad conclusions about them.

For its defeat had more to do with intraparty feuding, a series of divisive state issues and the personalities of the candidates than with any shift in ideology. It can be argued that Minnesota voters picked the more liberal candidate in selecting Republican David Durenberger, a Minneapolis lawyer, over Democrat Robert Short to succeed Sen Muriel Humphrey.

The conventional wisdom in Minnesota is that Hubert Humphrey, the great conciliator and perennial Happy Warrior, could have stopped the party's slide. Perhaps.

But when the DFL had its last great bloodletting, over the party's gubernatorial nomination in 1966, Humphrey, then vice president, tried to stop it and failed. Walter F. Mondale, now vice president, tried to stop it this year. And he failed.

Humphrey was always a more powerful force than Mondale in the DFL, which Humphrey helped found. He was the party's jolly uncle; Mondale is its smart kid brother.

Exactly what Humphrey could have done is another matter. Asked that question yesterday, one political observer joked: "He would have given a 2 1/2-hour speech."

There is little dispute that Jimmy Carter's selection of Mondale as his 1976 running mate and Humphrey's death last Jan. 13 set off the chain of events that led to Tuesday's election.

When Carter-Mondale won, then - Gov. Wendell R. Anderson, riding a tide of popularity, looked over the list of potential successors to Mondale in the Senate and decided he was the best man for the job. He then resigned, catapulting Lt. Gov. Rudy Perpich into the governor's mansion, and Perpich appointed him to the Senate.

When Humphrey died, his widow, Muriel, was appointed to his seat, thus giving Minnesota three top officials who were not elected to their current posts.

Rep. Albert H. Quie, the Republican gubernatorial nominee, captured the public outrage over this in a billboard ad. "Something scary is going to happen to the DFL," it read. "It's called an election.'

The DFL itself had planted the seeds of discontent. After Anderson had himself named senator, Democratic Rep. Donald M. Fraser "immediately started campaigning for the seat," one influential Democrat recalled yesterday. "For a year, Fraser supporters went around the state saying it was a bad thing for Anderson to appoint himself."

The party was already beginning to split over a series of emotional issues, including abortion, women's rights, gun control, and the controversial Boundary Waters Canoe Area in the northern wilderness.

Each issue developed a highly charged constituency. And by the time the party met in convention late last spring, it was severely factionalized. Anderson was the leader of the moderate wing. Short, who broke tradition by staying away from the convention, eventually became leader of its conservative wing.

Fraser, a 16-year House veteran, is the darling of the states liberals. He is also one of the last politicians who can claim a direct tie to the bitter battles that led to the party's birth.

The DFL Party was created in 1944 by fusing the state's Democratic Party with one of the nation's most successful third-party movements, the Farmer-Labor Party, in an effort to end Republican domination of state politics.

Humphrey was one of the founders of that movement, but in 1946, while he was mayor of Minneapolis, a radical faction outmaneuvered him.

Humphrey then launched a two-year counteroffensive aimed at taking party control from more radical elements and getting the party's nomination for the Senate in 1948. Two young associates in this battle were Orville Freeman, who later became governor and secretary of agriculture, and Fraser.

"This was a period when ideological and partisan passions could only be measured in degrees of white-hot intensity," Finlay Lewis has written in the Minneapolis Tribune. Politicians would routinely flay their opponents with such epithets as "warmonger," "Fascist" and "radical Commie."

The Humphrey faction, adopting a strong anticommunist, defense-minded posture, won the 1948 fight, and has controlled the party since.

At that time, a Macalester College student named Walter Mondale was first getting involved in politics, and a professor at St. Thomas College in St. Paul named Eugene McCarthy was running for Congress.

McCarthy became an antiwar Democratic presidential candidate in 1968, eventually losing the nomination to his old ally, Hubert Humphrey.

Fraser decided to run for Muriel Humphrey's Senate seat this year, and won the party's convention nomination. But Robert Short, the former owner of the old Washington Senators, baseball team and a longtime Humphrey fund-raiser, challenged him in a bitter primary.

Short pumped $800,000 of his own money into the primary, and launched a wholesale attack on Fraser's liberalism. Especially telling were his attacks on Fraser's support of abortion rights and his efforts to ban motor-boating and snowmobiling in the Boundary Waters Canoe Area.

Short won the primary. But the party never recovered, its formal structure refused to endorse him.

Meanwhile, the Independent-Republican Party nominated an attractive slate of candidates: Quie, a well-respected congressman with a confortable-shoe quality, for governor; Rudy Boschwitz, a plywood manufacturer who gained widespread exposure advertising his lumber products on television, to oppose Anderson; and Durenberger, an aide to Minnesota's last Republican governor, for the other Senate seat.

They all capitalized on a "throw-the-rascals-out" surge. On Tuesday they carried traditional Democratic areas in Minneapolis and St. Paul, piled up big margins in the rural heartland, and held down traditional DFL strongholds in the northern Minnesota Iron Range.

Anderson, who had carried Ramsey County, which includes St. Paul, by 3 to 1 as a gubernatorial candidate, lost it by 19,000 votes as a senatorial contender.

"I think people were just sick of us," said one influential party member. "The elections weren't even close. Short had his own liabilities. Wendy's (Anderson's) relationship with the party had deteriorated. And Rudy (Perpich) just didn't measure up to Quie man-to-man."

As late as Sunday, the Minneapolis Tribune poll showed Perpich maintaining a 4 or 5 percentage-point lead over Quie, and Anderson moving ahead of Durenberger.

"Nobody expected it," DFL Chairman Ric Scott said yesterday. "It wasn't in my guts. It wasn't in my head and it wasn't in the polls."

The DFL, party sources said, will now go into a intensive period of soul-searching and attempt to regroup. Its new leader likely will be Warren Spannaus, the state's popular attorney general, who easily won reelection.