Virginia Democratic Gov. Charles S. Robb said today that it has become "socially unacceptable" for many white males to support the national Democratic Party and said the party needs to broaden its appeal so some conservative voters "won't treat its candidates like they have an incurable disease."

Robb, speaking to reporters in Washington, also suggested that the Democratic National Committee abolish seven officially recognized caucuses of blacks, Hispanics and others because they perpetuate an image that the party is "nothing but a collection of special interests" with "undue influence."

"I view with great alarm the development of the single-issue phenomenon in American politics," Robb said during a luncheon with Washington reporters. He said the party should not abandon its commitment on social issues, but should appeal to a "national, not a narrow agenda."

He repeated concerns that the party, particularly in the South, is in danger of losing its majority status and could no longer afford to maintain its tradition of local and state Democrats running campaigns independent of the national party.

Asked how Democrats could appeal to white males, who overwhelmingly voted for President Reagan in the Nov. 6 election against Walter F. Mondale, and not lose crucial black support, Robb acknowledged "that's a challenge" and said he did not have a ready, simple answer.

Robb was in Washington to unveil a new book written by several Democratic governors on the future of the party, a collection of 14 essays that is the latest project in a growing effort by Democratic governors to play a more active role in national party affairs.

Robb, chairman of the 35-member Democratic Governors' Association, also is a leader in the search by elected officials to find a consensus candidate to become chairman of the DNC at the end of January.

The elected officials, including Arizona Gov. Bruce Babbitt and leaders in the House and Senate, are conducting a so-far-unsuccessful search for a party chairman who could unite factions of the party and serve as a party spokesman.

"We need to send a new message that we're not just a collection of special-interest groups," Robb said at the Sheraton Carlton lunch.

Robb met earlier in the day with House Democratic leaders to discuss the DNC chairmanship and later met with Kathy Vick of Louisiana, president of the Association of State Democratic Chairs, and Bob Slagle, Democratic chairman of Texas.

Slagle, outgoing Gov. Scott M. Matheson of Utah, Sen. Paul Tsongas of Massaschusetts, North Carolina Gov. James B. Hunt Jr. and Robb have all taken themselves out of contention for the job.

The governors and elected leaders have given themselves an informal deadline of mid-December to come up with a candidate or abandon the search out of fairness to several other candidates who are campaigning actively for the job.

Robb agreed the elected officials and party leaders may look weak if they do not solve the chairman problem, but joked, "Is there any image that we have right now that would be altered by one more failure?"