After years of ugly confrontations between City Hall and various minorities throughout the city, capped by a racially divisive 2001 mayoral primary, racial tensions in New York City seemed to have quieted over the last 18 months. A new mayor committed to soothing the racial storms and a City Council chock-full of new members, a large percentage of them blacks and Hispanics, have combined in part to make it so.

But a number of recent episodes suggest that race has re-entered the political conversation in New York, at least in discussions of sharing power.

Last week, members of the City Council accused Speaker Gifford Miller of supporting environmental racism by delaying action on a bill that would have tougher requirements for the removal of lead paint in city apartments. In that same week, members of the Democratic Party and others argued that Mayor Michael R. Bloomberg's attempt to remove party labels from municipal elections would hurt minority candidates.

Two months ago, the teachers' union sued Chancellor Joel I. Klein, accusing him of racial discrimination because the Bloomberg administration's plan to lay off nearly 800 classroom aides disproportionately affected blacks and Hispanics.

Further, Mr. Bloomberg's poll numbers among racial minorities are as low as some of the worst faced by Mayor Rudolph W. Giuliani, in spite of the Bloomberg administration's efforts to reach out to minority communities.

Why this is happening is a matter of much debate among Democrats and Republicans alike, and a matter of concern on both the legislative and executives sides of City Hall. At the very least, said political experts and aides to elected officials, the city could be on the verge of another racially charged set of municipal elections, potentially unlike any the city has seen since David N. Dinkins was mayor.