GEORGE BUSH has been a heavy user of the last tool left to presidents in a weak position with Congress - the veto. He has used it strategically to exert his relatively slight political leverage without cashing in his nice-guy image.
Friday when he vetoed a bill requiring employers to grant 12 weeks of unpaid leave to a parent of a newborn child or someone caring for an ailing relative, he was signing his 13th veto.
In the past three decades, the only president with a higher rate of vetoes was Gerald Ford. But unlike Mr. Ford, who had a quarter of his vetoes overridden, Mr. Bush has a perfect win record so far.
Because a veto blocks a bill after it has passed both houses of Congress, it is by nature an act of confrontation. Congress can override a veto with a two-thirds vote in both houses.
``Normally, a high veto rate means a president is not doing well with Congress,'' says Stephen Wayne, a Georgetown University political scientist. ``A veto is a sign of failure.''
But, he adds, ``I think with Bush it's a little different.''
Making a point
The Bush vetoes have not only derailed legislation that he disliked, they also made a point he felt he needed to make.
``Every time he has used it, it's to remind Congress not to mistake conciliation with weakness,'' Dr. Wayne says.
``He needs to show he's no pushover,'' says Charles Jones of the Brookings Institution. ``He's got to be careful as a conciliatory president. He can't let it go too far.''
Bush has used the veto to assert conservative positions, especially on abortion. Four of 13 vetoes so far have involved federal funding for abortion.
He has used the veto heavily to assert presidential authority when he felt Congress was encroaching on his prerogatives. At least four vetoes have been aimed at preventing the erosion of presidential authority.
Conservative activists find Bush a distinct improvement over President Reagan on issues of presidential power. Reagan talked publicly about the encroachments of Congress, but he mounted few real defenses against it.
``It's critically important that the president realize these things are not just about this or that issue but about the power of the presidency,'' says Dave Mason, director of executive-branch liaison at the conservative Heritage Foundation. ``Bush has recognized that.''
Bush gets strong ratings from professional politics-watchers for the deft way he handles his vetoes. He has been low-key about them, they say, and entirely predictable.
In general, he makes his veto threats early in the progress of a bill and spells out clear options for making the bill acceptable. On many bills, such as the savings-and-loan bailout measure last fall, the threat works and the legislation is adjusted enough to suit the administration.
On others, of course, he follows through on his veto threat. But he has managed to keep ill will and the political fallout to a minimum.
One reason is his straightforward way of dealing with Congress.
``Unlike some of his predecessors, he respects Congress,'' notes Mark Peterson, a Harvard political scientist.
Another reason is that he often claims the same goals promoted by the legislation he opposes. The political battle, then, ``becomes haggling over details,'' says George Edwards, an expert on president-Congress relations at Texas A&M University.
All these dynamics are at work on a civil rights bill now under debate in the Senate. The White House says that the bill as written will indirectly establish racial hiring quotas for private businesses. Unless the bill is altered sufficiently, the president says he will veto it.
But the White House aides have also shown clearly how badly they want the bill in some form. Bush's approval ratings among black voters are at historic highs for a modern Republican president, but to veto a bill with ``civil rights'' in the title is not a message the White House relishes sending. Reason for latest veto
But a similar equation did not stop Bush's veto of the Parental and Medical Leave Act. He supported such leave in his campaign, and he says he still does. But he objects to forcing the policy on business through a federal mandate.
Congressional leaders do not expect to mount an effort to override a parental-leave veto.
Meanwhile, the White House held off an override last week of a bill to allow greater political activity by federal employees by a mere two votes in the Senate.
However skillfully cast, President Bush's vetoes still underline his weak bargaining position against a Congress controlled by Democrats.
In his first year as president, he received the lowest congressional support in legislative votes of any first-year president since the weekly Washington-based publication Congressional Quarterly began tallying in the 1950s.