The Rev. Willie F. Wilson, a politically active Baptist pastor in Southeast Washington, endorsed the D.C. mayoral candidacy of Democrat John Ray yesterday after abandoning his leadership role in the campaign of Ray rival Sharon Pratt Dixon.

"People have the right to change their mind," Wilson told reporters after he endorsed a slate of eight Democratic candidates and one newly registered independent: Mayor Marion Barry, who left the Democratic Party to run this fall for an at-large D.C. Council seat.

Wilson, a longtime Barry supporter, relinquished his role as a Dixon campaign co-chairman earlier this year after she called for the mayor to resign in the wake of Barry's January drug arrest. Wilson had once hailed Dixon as "an angelic angel," and declined yesterday to discuss the rift, but a Dixon spokesman said it was caused by her strong criticism of the mayor's conduct in office.

"The separation was unfortunate, but necessary for both parties to feel clean," said David E. Byrd, Dixon's campaign manager.

Wilson and Ray said the minister's endorsement was given in return for Ray's pledge to help the Anacostia area of Southeast Washington, a poverty-stricken section of the District that has high rates of drug addiction, crime and teenage pregnancy, as well as other problems.

"I cross the river more than every four years," Ray, an at-large D.C. Council member, said, alluding to the section of the Anacostia River separating Wilson's community from the rest of the city. "My commitment has been here long before the election."

Wilson, pastor of Union Temple Baptist Church for 17 years, said he will use the final three weeks of the Democratic primary campaign to organize his 2,500-member congregation and nearby community residents on Ray's behalf.

Wilson also said he was untroubled by developer contributions to Ray, who has been attacked by some of his campaign rivals, notably Del. Walter E. Fauntroy, for accepting significant donations from segments of the real estate industry.

"I'm not averse to sitting at the table with anybody," Wilson said. "I want to talk with some of these developers. I think together we could make a difference."

Competing against Ray in the Sept. 11 primary are Dixon, a lawyer and member of the Democratic National Committee; D.C. Council Chairman David A. Clarke; Fauntroy; and council member Charlene Drew Jarvis (D-Ward 4).

Jarvis, who had courted Wilson's endorsement, said the minister's switch to Ray was "no problem."

"I'm sure he'll be switching to me before it's over," Jarvis said.

Republican Maurice T. Turner Jr., a former D.C. police chief, is unopposed for the GOP mayoral nomination. The general election is Nov. 6.

In other campaign developments yesterday, Ray's campaign announced he had mailed a flier defending his record on tenant rights to 45,000 apartment dwellers and renters in the District.

In recent weeks, as the mayor's race has heated up, Fauntroy has been especially critical of Ray for supporting a measure in 1985 that would have phased out rent control in certain units.

That proposal was part of a larger measure that the council enacted to extend the life of the District's rent control law.

Ray's flier says he "has supported and voted for every rent control law enacted by the city council," as well as lifetime tenancy for senior citizens and other pro-tenant bills.

Meanwhile, Jarvis, calling for a "full-scale war" on crime and illegal drug trafficking, proposed a six-point plan to establish more foot patrols for police and stiff fines to shut down crack houses.

"Our city cannot function as long as people are afraid to walk the streets," Jarvis said, adding that there is "no quick cure" in the effort against the drug trade.