It wasn't supposed to be a political speech, but California Gov. Edmund G. (Jerry) Brown Jr. couldn't resist.

Before addressing the concluding session of the eighth annual convention of Operation PUSH (People United to Save Humanity) here today, Brown was warned by PUSH's national president, the Rev. Jesse Jackson, that "in PUSH, we give no candidate blind loyalty. We give no party blind loyalty. Neither deserves it."

Brown, who was led into the convention auditorium as a choir sang, assured Jackson that his speech would be "nonpolitical." The he began.

The governor told his listeners that the national tax revolt, exemplified by California voters' approval of Proposition 13, was one example of the country's "shrinking back from the great commitment" to # equal opportunity and national unity. He did not tell them that he was a supporter, albeit a belated one, of the tax-limiting proposal.

Brown also said that continued racism, poverty and unemployment represented "a bomb ticking in the heart of the country."

"We're not going to survive as two nations or three nations - black, white, brown or yellow. We're not going to survive separately. Separatism leads to hate and paranoia."

As the message sank in, the audience responded enthuiastically. Then, gently and subtly, Brown told what he had done in California to bring the races together.

His administration has put more women and minorities, including blacks, in positions of authority than any previous state administration, he said. He pointed out that he had pushed for and approved urban aid proposals, child-care legislation and education programs - all close to the hearts of civil rights leaders.

As if to emphasize this point, a Brown aide quietly distributed a paper outlining what Brown has done for blacks and other minorities.

Brown ended his speech with a call for racial unity, which another round of enthusiastic applause.

But while some in the audience of nearly 600 persons momentarily enjoyed the excitement of Brown's presence and celebrity, many quickly headed for the exits as soon as he had finished speaking. They had planes to catch. CAPTION: Picture, Gov. Brown turns to the Rev. Jesse Jackson just before his speech to the convention of Operation PUSH. UPI