London in New York.

EDWARD KOCH, who has been mayor of New York longer than Margaret Thatcher has been prime minister of Great Britain, is seeking his fourth term. Given the ideological climate of the city, in which the moderately liberal Koch appears as a kind of Jesse Helms, he may well fail to win the Democratic nomination (in which case, he would run as an independent).

The interest of this election, though, centers on the possibility of a Republican victory, the first since John Lindsay's (if that counts). Since conventional wisdom holds that a Republican has to be a liberal to win in New York, the GOP front-runner, former U.S. Attorney Rudolph Giuliani, is seeking the endorsement of the city's small Liberal Party.

Giuliani, it must be noted, is not Lindsay 11. There is no liberal wing in the GOP nationally that seeks to puff him as the Second Coming, as Lindsay was puffed. Lindsay had a long and flamboyant record of liberalism as a congressman; Giuliani is a political )novice who made his name by placing handcuffs on people in front of television cameras. Some were criminals (which pleased conservatives); others were Wall Streeters (which pleased liberals).

But Giuliani's courtship of liberal favor is disturbing. New York is much worse off socially and structurally than it was when John Lindsay took office (John Lindsay's taking office accounts for much of the differential). The housing stock has declined drastically. The roads and bridges, turn of the century or older, are falling apart. The schools are a mess.

Addressing these problems requires a fresh and radical outlook, which Giuliani is unlikely to find among his new friends. Ronald Lauder, the cosmetics heir, who is challenging Giuliani for the GOP nod, would be a decent conservative candidate in a lean year. But he cannot escape the suspicion that he is a rich man looking to buy his way into politics when a more credentialed conservative is available.

Herb London, dean of the Gallatin Division of New York University, has come out against rent control and for school vouchers. He is a long shot for the Republican nomination, and a longer shot for mayor. But in a city that has a glut of politicians and a dearth of ideas, he fills an important need. The city will profit from his candidacy, and the Republican Party would do itself honor by giving him its support.