Carter, Reagan keep piling up delegates; Bush proving his 'Yankee pluck,' but the outlook for a big upset -- even in Texas -- grows quite dim

In beating Ronald Reagan in the Pennsylvania primary, George Bush showed himself trying to finish the GOP nomination race the way he started it -- with uncrushable Yankee pluck.

But for the Connecticut native and former United Nations ambassador, there doesn't appear to be another big state in sight for repeating his Pennsylvania popular vote upset of Mr. Reagan. Mr. Bush trails in Texas, his adopted state, where former Gov. John B. Connally backs Mr. Reagan for the May 3 primary.

Most of the West's 22 percent of the Republican convention delegates remain to be chosen the last month of the campaign. But the West is Reagan territory. So now Mr. Bush must campaign into Mr. Reagan's strength -- with California's winner-take-all delegate bonus awaiting the state's former governor, who leads Mr. Bush by 7 to 1 in the latest California Poll.

Bush campaign chairman James Baker says Maryland and Oregon are potential upset sites for his candidate, with Michigan, Ohio, and New Jersey also likely to yield Bush delegates.

But the Bush campaign now is resorting to the same talk of a last-ditch convention challenge that the Kennedy forces have used since early March to justify staying in an apparent losing contest. Nearly half the relublican convention delegates are unbound, free to vote their preference regardless of state caucus or primary results, Mr. Baker estimates. "There is no way anymore could get a lock on the nomination before the convention," he says.

Actually, according to Republican National Committee lawyers, the RNC is pledged to enforce binding on only two-fifths of convention delegates -- those bound by state law, not those bound to a candidate by state party rules. A proposal has been readied for the convention to drop binding even of delegates bound by state laws, which in effect would throw the convention wide open on the first ballot. Mr. Reagan is expected to have ample voting strength, however, to thwart such a proposal.

The RNC rules review committee has recommended that the party drop, for the 1980 convention in Detroit, its 1976 rule requiring the RNC to enforce state-law binding of delegates for the nomination. The RNC itself will formally take up the issue May 18 and make a recommendation to the July 14-18 convention.

According to RNC lawyers, only 768 delegates in 18 states -- 38 percent of the convention total -- are clearly bound under state law. Another 6 percent of delegates in four states are possibly so bound. A national convention decision to drop all binding would take precedence over state laws, RNC lawyers contend.

For Governor Reagan, Mr. Bush's popular vote upset in Pennsylvania only slightly delays his resuming a "corporate" or "presidential" strategy for the general election. Mr. Reagan's supporters want him to return to his less visible, more controlled early campaign style to reduce the risk of fumbling away the election.

By announcing advisers on military and foreign affairs and in other areas, and readying a list of Cabinet prospects, the Reagan campaign hopes to create the image of a candidate with a "corporation" of experts around him, to counter the charge he doesn't know enough in detail to run the White House.

Mr. Reagan's delegates tide passed the 600 mark by collecting more than half Pennsylvania's 83 delegates in the separate delegate balloting there. Counting California's 183 delegates and 50 other "sure" votes, the Reagan camp now claims 895 of the 998 delegates needed for a first-ballot convention win.

John Anderson's expected pullout from the GOP race, to try an independent route to the White House, is seen as helping Mr. Bush in the remaining GOP primaries and as helping likely nominee Reagan in November.

"Anderson has been a tremendous spoiler for us," Mr. Baker says. "We'd have won in Wisconsin if it weren't for Anderson. If he pulls out it's good for us -- and good for the Republican nominee in the fall.

"It will put us in direct opposition to Reagan, which was all the Republican candidates' goal last fall. We're only one month behind in our schedule. We wanted to be one-on-one with Reagan by the Illinois primary."

But Mr. Bush still has problems with his own candidacy, even without Mr. Anderson around to spoil things for him. "Bush has no natural constituency," says Kathleen Francovic, survey director for the CBS- NY Times polling operation that has sampled voter views after key 1980 primaries. "He's been the remainder man. Anderson seems to have usurped him among independents and Democrats who cross over. Bush gets some but fewer of those votes. Nothing much is said about Bush in our exit interviews. HE doesn't carry any one group."

The Pennsylvania outcome showed Mr. Bush gaining negative votes among those who did not want Mr. Reagan, but he has yet to create a positive, forceful image of his own.

Can a candidate like Mr. Bush come back, down 5 to 1 in delegates at the midpoint of a nomination race?

"We don't really know," says David Gergen, managing editor of Public Opinion magazine and an early Bush supporter. Mr. Reagan himself almost overtook Gerald Ford in 1976 after a poor early start, Mr. Gergen observes."But a Republican who has a natural constituency like Reagan would have an easier time coming back," he says.