New York — Charging that President Reagan's ''new federalism'' is a ''sham and a shame, '' New York Mayor Edward I. Koch has officially declared that he will run for governor of New York State.
''A great deal of thought has gone into this decision,'' Mayor Koch said at a packed press conference Feb. 22 at Gracie Mansion, the mayor's official residence. ''I love the job I have and the city which I serve . . . but over the last several weeks - following Governor (Hugh) Carey's withdrawal and the Reagan administration's presentation of its 'new federalism' - I have reconsidered that decision. After listening to friends and talking to other elected officials, I have concluded that the best course for me - and I believe for the people of this city and state -- is to seek the office of governor.''
Across the country, he said, ''the action is shifting from Washington to state capitals. Here in New York, counties, villages, towns, and cities will have to look to Albany for financial support, for new directions, and for leadership.''
Asked specifically whether New York State would gain at the expense of New York City if Mayor Koch were elected governor, the mayor reiterated a political theme that he has espoused since he was a US congressman: that he would ''represent all the people.''
''New York City residents would not be any better off than the constituents of Buffalo or Rochester,'' Koch declared. But he stressed at the same time that New York City residents would be better off with someone in office who has a ''proven track record,'' than someone who has not had a similar political trial by fire.
Before his huge landslide reelection as mayor last November, Koch had repeatedly contended that he would never seek higher political office than mayor of New York City.
But faced with the Gov. Hugh Carey's unexpected decision last month not to seek a third term and the devastating effects of ''Reaganomics'' on the city - coupled with what some close Koch observers saw as a weariness with and restlessness in City Hall -- Koch was forced to reassess his goals.
Mr. Carey's announcement threw the gubernatorial race wide open, for while Carey's popularity had declined sharply in recent years, he was regarded as a masterful campaigner who could draw upon all the benefits that go with being an incumbent.
Now that Koch has thrown his hat into the race, two likely candidates, City Council president Carol Bellamy and New York State Attorney General Robert Abrams, have dropped out because Koch is widely regarded as the the most popular Democrat in the state. And should Koch become governor, Miss Bellamy, who as City Council president is first in line to mayoralty if Koch steps aside, would become mayor -- in fact, New York City's first woman mayor.
It had seemed to many political pundits here that Koch's actions a month ago had been a tip-off to his gubernatorial aspirations. Then he had stepped up his criticism of Reagan economic policies, which, he said, will have a profound effect on the city's ability to upgrade its ailing services and perhaps even to balance its budget.
On the fiscal front, Koch's legacy seems to be more sound despite a recent study published here that his revenue projections for coming years may be inflated.
''I think the city is in better shape financially than it was five years ago and the budget should continue to be balanced,'' said Raymond D. Horton, an associate professor at the Columbia University Graduate School of Business, in an interview with the Monitor recently.
But there a number of reasons why New York City may fare worse under a Koch administration in Albany than it is doing now. Koch will have a tough time reversing a trend which has seen a decline in the city's share of state aid over the last decade, if he is to enlist the support of upstate Democrats for his gubernatorial campaign -- Democrats whose primary loyality is to cities upstate. For example, the city's share of state social-service aid fell from 71 to 61 percent from 1972 to 1980.
If he becomes governor of New York, he will be the first New York City mayor in recent history to go on to higher office. Also, as governor, Koch would be taken much more seriously as a possible candidate for president, as unlikely as this possibility seems to most political observers here.