RICHMOND, JUNE 6 -- Republican presidential aspirant Robert J. Dole campaigned in Virginia's conservative heartland today, picking up the endorsement of the state's junior senator and urging party activists to reach out to blacks and other minorities to capture offices from "the courthouse to the State House" this fall.

Dole, speaking at a political planning conference sponsored by fellow Republican Sen. Paul S. Trible Jr. (Va.), urged about 150 Republican regulars to court Hispanics, Asian Americans and other interest groups when pursuing municipal and legislative seats this year.

"It's going to take a long time of chipping away, chipping away, chipping away these groups from the Democratic Party," said Dole (Kan.). But, he added, "each of these ought to be Republicans."

At a news conference later, Dole acknowledged the difficulties in attracting minorities to the party, saying at one point: "It is tough with black Americans to make the inroads we should make."

Dole, whose 1988 presidential bid was endorsed by Trible today, said he will announce a statewide organization this month.

The Senate minority leader also took a few verbal swipes at Vice President Bush, suggesting to reporters that his own record in politics was far more substantive than that of the leading contender for the GOP nomination. "I've been voting, he's been talking," Dole said.

In the speech, Dole likened the current presidential sweepstakes to the 1960 contest between Republican Vice President Richard M. Nixon and Democrat John F. Kennedy, then a U.S. senator from Massachusetts. Dole reminded the audience that "the party that nominated a senator won, the party that nominated a vice president did not."

Dole received a generally enthusiastic reception, particularly when he said he would not "give up" on the Reagan administration's Strategic Defense Initiative, known as Star Wars, or on the "freedom fighters" in Central America and Afghanistan.