Will Reagan save the welfare state?

Could it be that conservative Ronald Reagan will sometime be viewed by history as the President who saved the welfare state? This fascinating possibility is raised by that long-time Reagan watcher Lou Cannon in his newly published book, ''Reagan.''

Cannon describes Reagan's spending-cut initiatives as having taken the steam out of a public reaction that might have otherwise destroyed the welfare state. Thus, concludes Cannon, ''Reagan may turn out to be the salvation of the New Deal much as his idol Franklin Roosevelt proved the savior of capitalism.''

Cannon had found among Reagan's liberal critics a recognition that Democratic social programs had gotten out of hand and needed trimming lest overreaction set in. Thus, while these liberals were denouncing Reagan budget cuts as ''heartless'' and ''inhumane,'' they were, according to Cannon, secretly delighted that a Republican President was wielding the needed ax.

Cannon may be right about this. Certainly the Democratic leaders, such as Tip O'Neill and Jim Wright, showed a certain ambivalence about Reagan's moves to shrink the spending for social programs. They stoutly defended these programs. But, even while criticizing the Reagan incursions into the welfare system, they conceded that some trimming was necessary.

Liberal Democrats in Congress, particularly in the House, always expressed or implied this same ambivalence. At no point did they put together any all-out, impassioned, concerted effort to save the welfare programs. They did resist Reagan to a degree. But their hearts weren't in it.

These liberals had read the public mood. They saw that cutbacks were in order. So there were doubtless many congressmen who agreed with the one quoted by Cannon: ''Some of our programs are out of hand and we can't cut them. Reagan can and it will save us, and him.'' This congressman, says Cannon, voted against the Reagan budget cuts and denounced the President for moving in that direction.

All this is not to say - nor is Cannon saying - that Reagan is a secret liberal and is surreptitiously trying to save the liberals' bacon.

Not at all. Reagan obviously seeks the economic salvation of the country in the encouragement and stimulation of the private sector. Further, there is no question about his intense desire to cut back the size and role of the federal government.

What it means, it seems, is that Reagan came on the presidential scene when reaction to the excesses of the welfare state was strong - and growing. And he has taken advantage of that mood to curb social programs.

But at no time has Reagan, as a governor or campaigner or President, called for the elimination of the welfare state. As a young, liberal disciple of FDR, Reagan hailed government's new role in helping individuals economically.

Since then his views have changed - but never to the point where he would do more than reform social programs and make them more efficient, perhaps by having some of them performed at the state and local level.

Cannon points out in this superb book that it was when Reagan was a staunch supporter of Roosevelt that he became a firm believer in lowering both taxes and tariffs. Thus Cannon sees this FDR influence as having something to do with Reagan's receptivity to the big income-tax cuts involved in supply-side economics.

So we have a President who somehow is able to idolize both Calvin Coolidge and Franklin Roosevelt. The Coolidge influence is more evident and dominant.But FDR, who brought about a social revolution in the country, still retains a subtle influence.