Campaigning in the region that cost him the Republican nomination in 1976, Ronald Reagan today demonstrated political strength among influential Republican party organizations.

At a press conference here this morning, Reagan declared that he intends to wage "an all-out campaign" to win the largely Democratic Northeast. As he spoke, he was flanked by prosperous looking GOP county chairmen who wield power and patronage in this "old politics" state, where 123 Republican delegates will be chosen March 25.

It is Reagan's low standing in the Northeast that has, at least until now, kept him from being a truly national politician. He has always felt uncomfortable and distrusted here, an impression that was reinforced in 1976 when the five key Northeast states -- New York, Pennsylvania, Connecticut, Massachusetts and New Jersey -- gave President Ford a total of 452 votes at the national GOP convention and Reagan only 49.

On the face of it, Reagan now has more delegates than that from New York state alone. Delegates here are named by party chairmen and run from congressional districts without being pledged on the ballot to any candidate. Candidates obtain support by getting chairmen to name delegates favorable to them.

Based on the announcements today, Reagan would have 61 delegate votes from New York state. In 1976, New York gave 133 delegates to Ford and only 20 to Reagan.

In neighboring Pennsylvania, where Reagan also spoke today, his 1976 running mate, Sen. Richard Schweiker, estimated that Reagan would gain at least 30 of the state's 83 delegate votes if he does well in the early primaries. Reagan had 10 delegates from Pennsylvania in 1976.

Reagan and his strategists also announced support in other states, including a 318-member committee in Connecticut and the backing of former U.S. Treasury secretary William Simon in New Jersey. The big prize here in New York was the support of former U.S. representative Bruce Caputo, long a target of the Reagan organization.

Reagan also may be facing problems in Saturday's Republican state convention in Florida. Campaigning today, he dismissed as "meaningless" the outcome of such straw polls.

His comment came as John Connally's Florida campaign chairman predicted "an upset victory [for Connally] regardless of what happens Saturday," and as Sen. Howard H. Baker (R-Tenn.), who was upset in a Maine straw poll vote two weeks ago, pulled out of the Florida contest.

Reagan is considered to have an edge in delegates to Saturday's nonbinding convention in Florida.

But while the frontrunner Reagan was piling up the endorsements, he was again raising doubts in some quarters about his knowledgeability on public issues.

Though his aides said he had been briefed beforehand, Reagan seemed totally uninformed about the federal assistance being received by New York City.

In 1975, this fiscally troubled metropolis was rescued by $2.3 billion in loans under legislation signed by President Ford.

Subsequently, President Carter signed a $1.65 billion loan guarantee which had as conditions a balanced city budget, federal approval of a financial plan and the ability of the city to raise money from other sources.

When Reagan was asked at a press conference where he stood on aid to New York City, he said that "no one in the country wants to hurt New Nork," but added that the city has the highest per capita cost of government services for any major city except Washington, D.C. His suggestion seemed to be that any aid should be tied to a reduction of these costs. When Reagan was then asked what he thought of the bills and the conditions approved by Presidents Carter and Ford, he replied:

"No, I've just said now I don't know what the reasons were or what their conditions were, but I've said what I think should be the answer to New York City's problems."