New York's liberal Democrats, led by Mayor Wagner (of all people), seem to have won their long struggle against the tight party control of Tammany leader Carmine G. De Sapio.

Ever since De Sapio bulldozed the State Convention into nominating Frank Hogan for the senatorial seat now held by Kenneth Keating, New York's liberals have been battling to loosen his grip on the party. At that time De Sapio's blatant display of political power raised the charge of "bossism" and undoubtedly helped sweep the Rockefeller-Keating ticket to victory in 1958.

Weakened by the loss of the governorship and by his small margin of victory in the primaries last fall, De Sapio has been on un-easy political footing for the past few months. And yesterday, by taking control of the state delegation to the Democratic National Convention, Mayor Wagner effectively ended De Sapio's national power, and reduced him to a mere county leader on the local scene.

The imminent demise of De Sapio is a welcome sign that the state Democratic Party is recovering from the Rockefeller fiasco. In the past two years, De Sapio has done more harm than good for the party, both on the national and local levels. While Mayor Wagner is not the most forceful of politicians, he at least will not be tainted with the label of "boss." And as De Sapio has been decidedly anti-liberal, New Yorkers can now expect to see a resurgence of the Lehman-Finletter-Roosevelt wing of the party. The moribund condition of Democratic politics in New York State seems to be over at last.