THE FACT THAT House Democrats have just elected Rep. Jamie L. Whitten (D-Miss.) as Appropriations Committee chairman, by a large margin, tells you something about the 96th Congress that you may or may not be glad to hear. It says that the ontesely liberal reformist/pro-consumer/pro-environmental faction there, the camp that has regarded Mr. Whitten as an implacable enemy, has lost much of its force. It also shows that the new open procedures for filling key posts can produce some outcomes as oldfashioned as this one, which apparently turned on many members' willingness to tolerate some philo-sophical differences with Mr. Whitten and trust him to be fair.

Some ideological line-blurring occurred in the Senate Republicans' caucus, too. There, contests for three second-level party leadership posts had all the makings of a showdown between the more-or-less moderate elements and the hard-charging "new right." As it turned out, two moderates and one conservative were elected, by margins ranging from one vote to three. Ideology seemed to be less decisive than personalities, friendships and desires for various kinds of balance in the party leadership.

Those two casesseem typical of whaths been going on. With one major exception (which we'll get to), the 96th Congress' organizing so far has been marked less by hard-edged left-right battles than by jockeying, consolidating and flank-protecting of a more intricate kind. Much of it has a timeless quaility. No matter what year it was, you could predict that Sen, Russell Long (D-La.) would try to get another pro-oil Democart onto his Finance Connittee; Sen, David Boren of Oklahoma got the nod this year.

Some choices do suggest how major issues are shaping up. For instance, the Senate Republicans put Sens. Jesse Helms (R-N.C.) and S.I. Hayakaw (R-Calif.) on the Foreign Relations Committee, giveing them a new forum from which to assail the administration on China and presumably on SALT. That might seem to intensify minority leader Howard H. Bakerhs problems on those issues. But it may also be a warning from the GOP leadership to the right, and to the Democrats, that foreign-policy disputes will really be settled on the Senate floor.

In the House, Speaker O'Neili seems to have eased the way for the hospital const-containments bill by making some sympathetic Commerce Committee alppointments and enticing Rep. Dan Rostenkowski (Dill/.), who helped kill the bill last year, out of a key subcommittee post on the Wasys and Means Committee.

The House leadership also tried, less succesfully, to maintain the liveral majority on the Budget Committee and keep th administrtion's program from being slashed before it even reaches the budget-cutters on the House floor. This is where left-right tensions and the liberals' vulnerability became most plain. The caucus asa whole refused to follow the leadership and voted to replace one of the panel's three liberals with conervative Rep. James R. Jones (D-OKla.). As a result of some procedural quirks, the liberal who was squeezed out in the process was Rep. Joseph L. Fisher (D-Va.), an outcome that we regard as a real loss.

Finally, it's real omen that the most widelysought committee assignments in the House this year were the money panels and Commerce, where so many battles over regulation will be fought. The Education and Labor Committee, where friends of social programs used to flocks, went begging; House Judiciary had to draft recruits. And there's an even better sign of what this Congress does not want to focus on: In both houses, nobody wants to serve on the ethics committees. Nobody at all.