Incumbent governors and senators nationwide easily turned back challenges yesterday as eight states held primaries, including a divisive contest for an open governor's seat in Washington state. Other states voting were Massachusetts, Minnesota, New Hampshire, New York, Rhode Island, Vermont and Wisconsin.

In New England, five-term Sen. Patrick J. Leahy (R-Vt.) easily won nomination, as did two-term Sen. Judd Gregg (R-N.H.). So did two first-term GOP governors: Vermont's Jim Douglas and New Hampshire's Craig Benson.

In the fall, Gregg will face Democrat Doris "Granny D" Haddock, 94, a political neophyte.

In Wisconsin, Gwen Moore, the first black woman elected to the state Senate, won the Democratic nomination for an open Milwaukee area House seat. The GOP race remained close.

In Washington, state Attorney General Christine Gregoire easily defeated Ron Sims, the King County executive and the state's most prominent black leader, in the Democratic gubernatorial primary. With 24 percent of votes counted, Gregoire had 72 percent to 23 percent for Sims. Dino Rossi, a former state senator, won the GOP nomination. Two-term Gov. Gary Locke (D) chose not to seek reelection.

In contested House races, longtime Rep. Sherwood L. Boehlert (R-N.Y.) beat back a conservative challenger who nearly defeated him two years ago. In Brooklyn, N.Y., Rep. Major R. Owens (D) easily won a three-way primary.

In Wisconsin, three Democrats and two Republicans vied to succeed Rep. Gerald D. Kleczka (D), who is retiring after 20 years. In two states considered battlegrounds for the presidential race, Republican hopefuls competed to challenge Democratic senators, contests that are receiving national attention and money because of the GOP's narrow 51 to 48 control of the Senate.

Former Army Ranger Tim Michelswon the chance to try to unseat Wisconsin's two-term Sen. Russell Feingold (D).

In Washington state, five-term Rep. George R. Nethercutt swept past five other Republicans to challenge Democratic Sen. Patty Murray, who faced token opposition.

Elsewhere, Sen. Charles E. Schumer (D-N.Y.) had no primary opposition.