Boston — Black people ought to support President Reagan and switch to the Republican Party, says Hosea M. Williams, a civil-rights militant who backed Mr. Reagan in the 1980 presidential campaign.
Mr. Williams predicts that Mr. Reagan's ''big mistake'' - the endorsement of tax-free status for private schools that discriminate against blacks - will prove to be advantageous to the civil-rights movement.
In the short run the President ''backed down,'' limited his tax-free order, and offered legislation to support his new stand, says Mr. Williams. In the long run Mr. Reagan will give minority business more support, adds Mr. Williams, who will lead a black business mission to Japan in the spring. ''And it proves to us that we black people have clout when we stand for what's right,'' he says.
Mr. Williams was among 65 black Republicans - members of the National Black Republican Council - who participated in a White House briefing Jan. 28 while black civil-rights leaders gathered in another part of the nation's capital to sharply criticize the President. The council met in Washington in conjunction with a three-day session (Jan. 27-29) of the Republican National Executive Committee.
''We plan to support the President's program and try the new ideas he is offering the nation,'' said LeGree Daniels, newly elected chairman of the National Black Republican Council. ''We believe we can work with the administration and sell this program to the community. I am not doom and gloom. I believe we black people are mature enough to work with the GOP and achieve our goals.''
While this group held ''frank discussions'' with the President and White House advisers, members of the Black Leadership Forum, including Dorothy Height, president of the National Council of Negro Women's Clubs, H. Carl Holman of the National Urban Coalition, and the Rev. Joseph E. Lowery of the Southern Christian Leadership Conference (SCLC), sang another tune.
''We oppose the President's retreat on the federal commitment to deal with the poor and minorities, his lukewarm support of the extension of the Voting Rights Act, and his 'new federalism,' to us the return of state's rights,'' says Miss Height.
The SCLC plans a voting rights march ''soon'' in Alabama to oppose the jailing of two black women in Pickens County for alleged vote fraud, says Mr. Lowery.
One favorable comment was expressed by Mr. Holman. He likes job enterprise zones for cities, but warns: ''It would be a vast mistake to sell this as reform. It is more of an experiment. Plans call for only 75 enterprise zones in three years. It has potential for those communities fortunate enough to be selected.''
Still sporting his bushy Afro, now showing a touch of gray, and a beard, Hosea Williams remains pro-Reagan. He says he offered two black priorities at the White House meeting:
* Economic recovery - ''Help black businesses enter the mainstream, and black entrepreneurs will hire thousands of their own people.''
* Urban enterprise zones - Encourage minority enterprise to be involved in setting up and offering employment where the jobless live.
Times have been rugged for blacks who supported Reagan in 1980, says the Atlanta minister. Two supporters - Mayor Charles Evers of Fayette, Miss., and South Carolina state Rep. Mordecai Johnson - have since been voted out of office.
The Rev. Ralph D. Abernathy, president emeritus of the Southern Christian Leadership Conference, retains access to the White House. And Mr. Williams, a five-term Georgia state representative from Atlanta, says, ''If elections were held today, I would lose.'' But he quickly adds that he expects to be returned to office in November.
He offers this advice to blacks who are ''cold'' toward the Republican administration: ''Drop the welfare philosophy; stop begging. Social programs have outlived their usefulness. The war on poverty was lost because by the time it trickled down to the poor, all they received was advice.''