Oval Office True Grit

BY threatening to veto a $16.4 billion package of spending cuts being offered by the Republican Congress, President Clinton has begun sounding more like his purported idol -- Harry Truman -- and less like 19th-century presidential wannabe Henry Clay, ''the Great Compromiser.''

Mr. Clinton has taken pains not to be unduly belligerent toward the GOP Congress. Both his personal nature and his political instincts have caused him to seek accommodation over confrontation, even when fellow Democrats have urged a tougher approach.

But the president now appears to have found his line in the sand over a recision bill for the 1995 budget just agreed to by House and Senate conferees. He had expressed approval earlier for a $15.7 billion version that had passed the Senate. But in the final bill, Republican leaders apparently have decided to test Clinton's resolve, loading it with provisions sure to irritate him. The bill cuts back funds for education and for AmeriCorps, the youth national service program that the president holds especially dear. And it removes a provision to ensure that the savings go toward reducing the deficit and not toward a huge tax cut GOP leaders want.

To make the bill hard to veto, it contains new spending provisions, including $6.7 billion in disaster relief for California and elsewhere and $250 million the president has sought to fight terrorism. It also contains $275 million in debt relief for Jordan that the US has promised as part of the Middle East peace process.

But GOP leaders may have miscalculated. The two-thirds majorities needed to override a veto are nowhere in sight. And Congress could still pass the elements of the bill that it agrees with Clinton on -- or look as though it's the branch unwilling to act. Nor can Republicans cry that Clinton offers no alternative. The president has unveiled his own recisions package, which amounts to $16.5 billion, just slightly more than Congress proposes.

When you add in White House pronouncements that the president is still willing to negotiate to avoid a veto, Clinton is also winning the ''who sounds most reasonable'' contest.

Clinton's GOP predecessors Reagan and Bush wielded their constitutional power in 122 vetoes. Clinton finally seems ready to cast his first.