WASHINGTON -- President Bush and Gov. Bill Clinton rolled over essentially token opposition in presidential primaries in Pennsylvania yesterday and moved a step closer to a head-to-head confrontation in the general election Nov. 3.
Mr. Clinton defeated former Gov. Jerry Brown of California by what appeared to be a margin impressive enough to give the Arkansas governor a strong case to make when he flies to Washington today to seek the support of uncommitted "superdelegates" from the Senate and House.
With 90 percent of the precincts reporting, Mr. Clinton had racked up 631,060 votes, or 56 percent, compared to 288,281, or 26 percent, for Mr. Brown. Former Massachusetts Sen. Paul E. Tsongas, who dropped out of the race weeks ago, received 13 percent of the vote.
Mr. Clinton took heart from his victory.
"We were able to run the most positive, issue-oriented, change-oriented campaign that I've had the honor of running," he said. "I was able to talk about my life. . . . I was able to talk about my record as governor."
Meanwhile, Mr. Bush could claim at a party fund-raising dinner in Washington last night that his defeat of challenger Patrick J. Buchanan had put him "over the top" -- meaning that it had given him enough delegates to assure him of the 1,105 he needs to be renominated at the GOP convention in Houston in August. With 93 percent of the precincts reporting, Mr. Bush had 677,774 votes, or 77 percent of the vote, compared to 205,900, or 23 percent, for Mr. Buchanan.
"It's wonderful to be officially over the top," Mr. Bush told the dinner crowd of 4,000. He thanked everyone "who participated in the primary process to make these 1,105 delegates possible."
In the most intriguing and perhaps politically significant race of the day in Pennsylvania, Lynn Yeakel, a longtime social activist but neophyte politician, beat Lt. Gov. Mark S. Singel for the Democratic nomination to oppose Republican Sen. Arlen Specter in the general election.
With 65 percent of the precincts reporting, Ms. Yeakel had 357,220, or 46 percent, to Mr. Singel's 246,799 votes, or 32 percent. Three other candidates split the remainder.
"Somebody said it couldn't be done. In fact, lots of people said it couldn't be done, and we did it!" Ms. Yeakel declared in a victory speech.
With 65 percent reporting in the GOP race, Mr. Specter had handily defeated his conservative rival, state Rep. Stephen Freind, 65 percent to 35 percent. Mr. Specter had 375,823 votes to Mr. Freind's 197,983.
But the Republican incumbent now faces what politicians in the state consider a serious challenge from Ms. Yeakel, who entered the campaign in angry reaction to Mr. Specter's prosecutorial role toward Anita Hill in Senate Judiciary Committee hearings on the nomination of Judge Clarence Thomas to the Supreme Court.
The only suspense in the presidential voting was on the Democratic side, where results were studied for evidence on whether Mr. Clinton has begun to shed the political baggage he acquired in earlier primaries.
Mr. Clinton's performance was depreciated by the perfunctory quality of the opposition from Mr. Brown ever since his weak showing in New York three weeks ago. But the front-runner's total, coming in an industrial state critical to the Democrats in November, gave his campaign a fresh gloss nonetheless.
A poll of voters leaving polling places found only 33 percent harboring doubts about his honesty and integrity, compared with 46 percent in New York April 7. But, although the proportion had declined, half the Democrats here said they would have preferred the choice of other candidates.
The exit poll also showed Ross Perot, the Texas billionaire and prospective independent candidate, with a respectable base of support in both parties: 23 percent among Democrats, 24 percent among Republicans.
Mr. Clinton entered the primary with 1,388 of the 2,145 delegates needed for the nomination, according to an Associated Press tally. His success in Pennsylvania was expected to give him more than 1,500 and allow him to focus more attention on those 772 superdelegates, about 300 of whom already have indicated a preference for him.
But the question all along was whether Mr. Clinton could resolve doubts about his potential, doubts raised by his handling of such personal issues as whether and when he smoked marijuana and how and when he avoided the draft in the Vietnam War. The issues were given renewed attention in the primary when Democratic Gov. Robert P. Casey made a public point of questioning whether his colleague could win in the fall.
Mr. Clinton tried to change the subject by using the Pennsylvania campaign largely as a forum for a de facto beginning of the contest with Mr. Bush. His major events in the desultory three-week campaign were speeches on the economy and the environment in which he taxed the president in harsh terms. Meanwhile, he ignored Mr. Brown, even refusing to join in a single debate.
Up to a point, the strategy appeared to work. Mr. Clinton avoided the embarrassment he suffered in New York, when Mr. Tsongas ran second to him with 29 percent of the vote after having stepped to the sidelines. And the size of his margin over Mr. Brown seemed to reduce the former California governor to the status of nuisance candidate.
"I don't care what the numbers show," said Mr. Brown, declaring that he would press on.
The question of whether Mr. Bush had officially locked up the 1,105 delegates needed for renomination was largely a quibble over political mechanics. The 72 delegates he won here left him 13 short of 1,105 by the AP count.
But the president already is also assured of 22 from Maine and 8 from Wyoming.