Democrats are launching a frontal attack on the slim - and still unofficial - Republican lead in the ballot count for governor of New Jersey. With all ballots in, the Nov. 3 election is still undecided, and now the Democratic National Committee is asking the US Justice Department to investigate whether the Republicans violated the Voting Rights Act by ''intimidating'' black voters.
The committee has hired Drew Days Jr., a former Carter administration civil rights prosecutor, to assemble charges against the Republicans.
Republican Thomas H. Kean has been given an unofficial lead over Democrat James J. Florio of less than 2,000 votes out of the 2.28 million votes cast. Some ballots are being recounted.
Mr. Florio complained that the National Ballot Security Task Force, funded by the Republican National Committee, had made a ''conscious effort to intimidate'' Democratic voters by displaying posters at inner-city polls that read: ''Warning. This area is being patrolled by the National Ballot Security Task Force. It is a crime to falsify a ballot or to violate election laws.''
The New Jersey attorney general's office reported no complaints of voter intimidation.