The litany is familiar: Rep. Parren J. Mitchell, fighting for the poor to receive better housing.

Outspoken Maryland Democrat Mitchell, advocate of minority businesses.

Liberal Mitchell, chairing the House Small Business Committee.

The small business committee? The watchdog of the nation's 13 million, mostly white, mostly conservative small-business owners?

Mitchell -- who as a teen-ager picketed many small businesses during civil rights marches -- is now in line to be their chief advocate in the House of Representatives. Committee chairman Neal Smith (D-Iowa) resigned last month.

"At first I was concerned Parren wouldn't rise above his main interest of minority enterprise," said John Motley, deputy director for federal legislation at the National Federation of Independent Business.

"But so long as the committee doesn't become a minority enterprise committee and [Mitchell doesn't] allow his subcommittee chairmen to do their own things," Mitchell and the samll business groups should get along just fine, Motley added.

He said NFIB is eager to work with Mitchell and thinks he'll be better than former chairman Smith, whom he criticized for narrow-mindedness and inaccessibility. But the group, which rates senators and representatives at the end of each session, gave Mitchell one of its lowest ratings because he voted their way only twice on 19 specific issues.

"He's assuming a chair, and he realizes the interests of the [small business] constituency group may be different from issues he's voted for before," Motley said. His main constituents, Motley continued, have been his own home district in Baltimore and blacks. Of Mitchell's new small-business constituency, Motley said, "While that may not have been one that he may have had in the past, he will be very open about it."

Mitchell, a small business committee member since his election to Congress in 1970, wasn't directly in line for the chairmanship. He leapfrogged several representatives who chose other committees or were defeated in the last election.

His new chairmanship shouldn't conflict with his image as a civil rights fighter, Mitchell said. In fact, one congressional aide who has worked with Mitchell said, "He's shown he's willing to be unconventional and not follow what's considered to be dogma on minority economic issues."

For example, Mitchell supports the Federal Reserve Board's policies of restricting the money supply gradually, a position that small business owners would embrace because it could lead to lower, stable interest rates. And in the long run, such policies could help the poor by reducing inflation and producing more jobs, Mitchell has said.

"There are two perceptions of me out there. As a member of Congress who worked most closely with minority small businesses and as a fighter for fair housing and a fighter against discrimination," said Mitchell. As for his new role helping not only minority businesses but larger white-owned firms, Mitchell said, "I haven't had any problem dealing with that."

Given the recent national swing toward the right and Mitchell's new constituency, will be become more conservative?

"No," he replied emphatically. "I'm not ashamed. I am a liberal, and I always will be."

In the past, perhaps, small businesses should have looked toward Democrats and liberals more as allies rather than toward conservatives and Republicans who seem to favor big business over small, said Paul Serotkin, a spokesman for the Smaller Business Association of New England.

"We've ignored working with the Teddy Kennedys in the past, and that was wrong," said Serotkin.

"We're looking for real dynamic people," Serotkin said. "Mitchell already has a name. That may put us more in the spotlight, and that should help us."

In the past, the post wasn't considered particularly important. Serotkin said Smith was more concerned with farm issues and his other committees than the small-business concerns. But 13 million small businesses across the country are becoming a more powerful, more vocal lobbying force -- like the downtrodden that Mitchell already is known to help.

"There's been much more interest in small business and minority business" in the past 10 years, Mitchell said, displaying a contemplative frown. "Many of the members of Congress saw what was happening to small businesses in their districts" as far as regulations and economic conditions that hurt them.

One of his first acts as chairman will be to poll committee members on what they think should be done and then follow through on recommendations made at the White House Conference on Small Business last January.

"I don't see any attacks" on small business programs from the Reagan administration, Mitchell said. "I don't see this incoming administration attempting to demolish these programs, probably for political reasons."

Mitchell may have some demolition plans of his own. The Small Business Administration, recently wracked by scandal after scandal, needs to be tightened up, Mitchell said. But the congressman said he first wants to see what the Reagan administration wants to do with it.

For example, Mitchell said, "The SBA frequently says its bank participation loan program is excellent. What we hear around the country is it's not excellent."

Mitchell said he also would advocate "abandoning the usual political practice of placing people in the SBA as a matter of political patronage" and seek out people with business experience. "It's hard for people who've never been in business to understand how business works."

Mitchell said he also hopes to meet quarterly with representatives of all the major small business trade associations and attempt to hold hearings frequently around the country to get views from outside Washington.

For example, Mitchell said he sent one of his staff members to an SBA district office in Louisiana because an SBA official said the office didn't give out direct loans to small businesses, which is contrary to the agency's policies. "There's a great deal of ignorance and confusion about the whole small business program," Mitchell said.

Mitchell also said he will try to encourage small businesses to move into exporting to help them create more jobs for the unemployed and to determine what aid they need during times of economic uncertainty.