California Assemblyman Willie L. Brown is a flamboyant liberal who electrified the 1972 Democratic National Convention with an impassioned plea of "give me back my delegation!" after the credentials committee had refused to seat the McGovern delegation that Brown co-chaired.

For the last few weeks, Brown has been addressing his rhetoric to conservative Republican colleagues in the Assembly: "Give me the speakership." This time he bargained and got what he wanted.

In the process, the Republicans got some things they wanted, too. In committee assignments and other day-to-day Assembly functions, the minority party will have a greater say than in the past. More important, staff and money to prepare for the reapportionment that will begin in January will now be split half-and-half between the two parties.

Democrats have controlled reapportionment in California for the last two decades, and they have drawn as many safe Democratic districts as they could. Now, with a greater say in reapportionment combined with the rise of conservatism, the Repubicans will have a good chance to gain control of the state's largest-in-the-nation congressional delegation in 1982. Republicans now trail Democrats 22-21 in the California delegation after making a net gain of three seats in the Reagan landslide.

Most assembly Republicans agree that, deal or no deal, they are happy with Brown, often described as the brightest member of California's 80-member Assembly and a man who makes good on promises.

Brown's election as the first black speaker ends a period o bitter feuding among Assembly Democrats that began last December when neither then-Speaker Leo McCarthy nor his challenger, Howard Berman, could gather the required votes within the majority caucus.

Both the McCarthy and the Berman forces spent small fortunes in this year's primary and general elections, trying to elect Democrats who would back their man in the speaker battle.

Initially, Berman appeared the victor, and McCarthy took himself out of the race. But animosity from the year-long feud ran deep, and it was apparent that no Democrat would win in caucus. So Brown, the longtime champion of liberal causes, announced that he was a candidate for speaker, and he began to cultivate the Republicans who would cast the deciding votes on the Assembly floor.

When Brown announced last week that he had the votes to win, 23 Democrats and 28 Republicans, observers remembered that he had thought he had the votes once before, in 1974, but had lost. A colleague joked then that "the little black kid can't count [votes]."

Monday, after being elected speaker by 23 Democrats and 28 Republicans, an exuberant Brown bounded to the Assembly podium and, pausing before gaveling the 1981 session to order, remarked with a smile, "Now, the little black kid can count."