Can House budget coalition give Reagan his tax cut too?

The Reagan victory on his budget was a shot heard all around the United States. It has given new strength to the revitalization taking place in the Republican Party, reinforcing its drive upward -- now focused on the 1982 elections.

And it has sparked editorials commenting on the growing evidence that President Reagan does, indeed, possess leadership qualities.

But what of Mr. Reagan's "hand-to-hand combat," as one White House aide characterizes the President's impending struggles over individual budget cuts, particularly those that affect social programs? Will he be able to hold the new Democratic-Republican House coalition together in his efforts to get a three-year tax cut of 10 percent for each year?

The assessment from knowledgeable observers comes down to this:

The President's impressive budget victory, in which he persuaded 63 Democrats to jump ship and vote with him, gives him some important political momentum as he moves toward showdown votes on his economic package.

But the emerging view here is that Reagan will find conservative Southern Democrats slow to support his big tax slice.

Instead, these conservatives put their emphasis on an effort to achieve a balanced budget, expressing anxiety that such a big tax cut would defeat that purpose while fueling inflation.

Many Republicans share these misgivings about the President's "supply side" economics and therefore cannot be counted on to give him the 100 percent backing on his tax-cut measure that they gave him on the budget vote.

The major challenge for the President apparently will come on votes that many Democrats view as a battle to save portions of legislation that embraces New Deal philosophy.

The key question: Will the liberals stand up and fight?

Up to now the liberals have talked about their unhappiness mainly in muted tones. Speaker of the House Thomas P. (Tip) O'Neill Jr. (D) of Massachusetts has been particularly quiet.

But with the budget vote over, House liberals may be plotting a vigorous stand against the Reagan incursions into their favorite programs.

Speaker O'Neill now is saying that it is time to talk and act tough. He indicates he may be ready to assert his leadership in a confrontation with the President.

But will the Democrats be able to take advantage of their majority in the House and save the day for social programs now on the books? Or will they be looking over their shoulders at voters back home, who now more than ever after the budget vote seem delighted with the President's plans for cutting government spending?

At the moment, the President is riding high in opinion polls that reflect public perception of the way he is handling his job. New polls following the budget vote might well send his ratings even higher.

Observers here are pretty much agreed that if Reagan can maintain this kind of support, he will continue to be most formidable in his battles with Congress -- perhaps unbeatable.

Right now the consensus here -- from politicians as well as the news media -- is that Reagan is going to get most of his tax cuts and much of his tax r eductions. Indeed, they say, it looks like a Reagan year.