Republicans in Congress -- often prone to quarrels between conservative and moderate wings -- are showing vastly more unity under President Reagan than under the three previous GOP leaders, Eisenhower, Nixon, and Ford.
In fact, both parties showed unprecedented discipline in last week's budget drama. In one vote the Democrats held 85 percent of their members, the Republicans an extraordinary 99 percent. Only two of 190 Republicans wandered from the GOP column -- and one of these simply put his voting card in the wrong slot.
And despite the prominent role of Southern "boll weevil," Democrats last week , congressional experts say this group has only a fraction of the impact on national politics that it once had. By historical standards, the movement of conservative Democrats to Republican ranks for the House budget test -- while enough for narrow GOP victories -- was modest.
Thus the switch to the Republican column of 25 Southern Democrats and four Democrats from outside the South on a key vote does not suggest a "new coalition" of Democratic conservatives and Republicans, as the Reagan White House quickly proclaimed, these experts say.
The conservative coalition of Southern Democrats and Republicans has been a force in American politics since the 1930s, congressional historians say. The coalition even began to thwart Franklin D. Roosevelt after his early successes.
The conservative coalition dominated American politics at times during the 1940s and 1950s, when half of all Democrats in the House and Senate were from the South.
"From the 1930s even into the 1960s, 90 to 100 Southern Democrats would vote with the Republicans," observes Norman Ornstein, Catholic University expert on Congress. "Now you're talking about less than 30. That's good news for the Democrats. They actually have more unity now than in the good old days."
On the budget votes last week, the two parties showed more unity than in any period since the early years of President Woodrow Wilson (1913-21), Mr. Ornstein says.
In the past 25 years, despite conservative defections, the Democrats have been more likely to follow presidents from their own party. Until President Reagan's term, the Republicans were more likely to wander under GOP presidents.
Under President Eisenhower, 60 percent to 79 percent of House Republicans voted with the President, averaging 68 percent from 1955 to 1960. House Republicans voted with President Nixon 73 percent of the time from 969 to 1974. President Ford had his own party's members with him only 65 percent of the time in his three White House years, on votes where the Ford administration had declared a position.
The Democrats backed President Kennedy an average of 83 percent of the time in his three years, President Johnson an average of 81 percent from 1964 to 1968 .
"What's different now is the remarkable unity of the Republicans," says Thomas Mann, a congressional affairs expert. "It enables a small number of Southern Democrats to make a difference. In the '60s and '70s, this many Democrats or more would break away, and it made no difference."
"The House Democratic leadership thought they had the votes to force a review of the Reagan budget," Mr. Mann says. "they knew it would be close, but they thought only 15 or 20 Southern Democrats would defect.
"The White House lobbying -- the President's speeches, the phone calls -- made the difference at the margins," Mann says. "But it's too early to suggest Reagan now controls Congress. [At one point] if only four people had voted differently, we might be saying the White House overreached."
The conservative coalition of Southern Democrats and Republicans has shown wide swings in its effectiveness in the past quarter-century in House votes. It had its best year in 1959, winning 91 percent of its tests. But in 1960, Eisenhower's last year, it won only 35 percent of roll-call votes.
The bottom for the conservative coalition was 1965, the height of Johnson's Great Society successes, when the coalition prevailed on only 25 percent of roll-call votes against the majority Democrats. But by 1967 it was winning at a 73 percent rate again -- the same level as in 1979, the year of President Carter's doldrums, when he claimed the nation had sunk into malaise.
In terms of presidential victories in the House, history shows some presidents quickly lose strength, while other hold up rather consistently.
Eisenhower's 91.2 percent victory rate in 1953 had ebbed to 55.5 percent in 1959. Kennedy held steady in the 93 percent range. Johnson had the best year among recent presidents with 93.8 percent in 1965, but slipped to 75 percent in 1967.
President Nixon fell from 84.6 percent in House victories in 1970 to 48 percent in 1973. But even with Watergate fast closing in, Nixon's success rate in 1974 rose to 67.9 percent.
It was Ford who found the nadir in House victories among recent presidents -- 43.1 percent in 1976. Carter, despite his image as an inept handler of Congress , managed to average a 72 percent victory rate his first three years in office.