Hotly contested Democratic primary races in California, Iowa and North Carolina will be settled today as voters go to the polls in nine states on the busiest day so far of the 1990 election year. Other states holding primaries are Alabama, Mississippi, Montana, New Jersey, New Mexico and South Dakota.

Two late polls in the bitterly fought race for the Democratic nomination for governor of California showed former San Francisco mayor Dianne Feinstein increasing her lead over state Attorney General John Van de Kamp.

Mervin Field's California Poll reported that the 3-point lead Feinstein held in the last poll had opened up to an 8-point advantage, 42 to 34 percent, among likely voters in polling that concluded Sunday.

The Los Angeles Times poll showed Feinstein with 42 percent and Van de Kamp with 29 percent. Twenty-nine percent were undecided or supported one of nine other candidates on the Democratic primary ballot.

Sen. Pete Wilson has only token opposition for the GOP nomination to succeed Gov. George Deukmejian (R), who declined to seek a third term.

In an attempt to boost his support among women, Van de Kamp appeared on the steps of the Los Angeles County courthouse Sunday with Norma McCorvey, the "Jane Roe" of the landmark Supreme Court Roe v. Wade abortion-rights decision. "I have no criticism of Mrs. Feinstein's record," McCorvey said. "But I believe John Van de Kamp is the candidate who will do the most to protect a woman's right to choose."

Abortion also has been a major issue in Iowa's Democratic gubernatorial primary where the National Abortion Rights Action League has supported Iowa House Speaker Don Avenson against anti-abortion rival Tom Miller, the state attorney general.

A poll published Sunday in the Des Moines Register showed that Avenson had moved into the lead with support from 32 percent of those surveyed, compared with 25 percent for Miller. Farmer-banker John Chrystal was at 19 percent. The winner will face Gov. Terry Branstad (R).

North Carolina Democrats choose a challenger to take on Sen. Jesse Helms (R) in the fall. Southeastern region District Attorney Michael Easley, trailing in polls in a runoff against Harvey Gantt, campaigned in the eastern part of the state, telling supporters, "If we have a big turnout in the east, Mike Easley will win the runoff. If we don't, it'll be real close."

Gantt, a former mayor of Charlotte who is seeking to become the first black to win statewide office in North Carolina, campaigned over the weekend in the northeast section of the state, which has a high percentage of black voters who were crucial in the May 8 primary in which Gantt led a six-man field.

In New Mexico, where Gov. Garrey E. Carruthers (R) is ineligible to seek reelection, both parties have competitive gubernatorial primaries. A poll published Sunday in the Albuquerque Journal showed state Senate Minority Leader Les Houston and former legislator Frank Bond each with 29 percent support among Republicans surveyed.

On the Democratic side, former two-time governor Bruce King had the backing of 43 percent, while state Attorney General Paul Bardacke was supported by 32 percent.

Four Democrats were locked in a close race in Alabama for the Democratic nomination to oppose Gov. Guy Hunt, the first Republican to hold that office since Reconstruction.

Former governor Fob James and state Attorney General Don Siegelman were neck and neck in two late polls, followed closely by Rep. Ronnie Flippo and educator Paul Hubbert. If no candidate wins with a majority, the top two finishers will meet in a June 26 runoff.

The Montana secretary of state predicted a low turnout in that state's Republican Senate primary, which should favor Lt. Gov. Allen Kolstad over businessman-inventor Bruce Vorhauer. The winner will take on Sen. Max Baucus (D).