In the American Civil Liberties Union office a few blocks from the Capitol, John Shattuck is fielding phone calls from reporters. Attorney General William French Smith has just launched a major attack on the federal courts for finding too many ''implied'' rights in the Constitution, and the ACLU is responding.
Reading from a hastily drafted statement scribbled on a yellow pad, Mr. Shattuck shoots back that winning a presidential election does not give the Reagan administration license to run the judicial branch, too.
The ACLU, founded 60 years ago to defend individual rights, routinely wades into such disputes. But even for this controversy-prone group, which two years ago infuriated much of its liberal membership by backing the Nazi Party's right to march, these are extraordinary times.
A year ago, Shattuck, legislative director and chief lobbyist for the ACLU, thought his office was busy, arguing from time to time with the Carter administration and trying to pass bills through Congress. Now those days seem like easy times.
''The difference is that we are now fighting a combination of a hostile government and very strong, hostile political force outside the government'' on civil liberties issues, he says.
While administration officials deny that they are hostile to civil liberties, the new administration and the ACLU have been at cross purposes almost from the start. Presidential counselor Edwin Meese III fired the first shot last May when he called the ACLU part of a ''criminals' lobby'' because of its efforts on behalf of convicted criminals. Mr. Meese later backed away from the statement, but not very far. (A Department of Justice spokesman recently joked that whenever the ACLU and New York Times oppose a stand, ''Then we think we're right.'')
Meanwhile, outside of the government, groups such as Moral Majority, the National Conservative Political Action Committee (NCPAC), and others from the New Right have grown powerful.
''They have their view of civil liberties,'' concedes Shattuck. But it is certainly not the ACLU view, which emphasizes free speech, separation of church and state, abortion rights, and desegregated schools, as well as protection of the rights of criminal defendants.
The far right is trying to ban abortion, halt busing for desegregation, put prayers into public schools, and roll back gains for women's rights, says Shattuck. ''They want to revive the engines of internal security like the House Un-American Activities Committee,'' he adds. (The ACLU is watching a petition circulating in the House of Representatives to reinstate the defunct HUAC, which once investigated suspected communists.)
''At the same time we have the Reagan administration,'' says the ACLU lobbyist. ''It is often feeling pressures from the New Right. This makes our work extremely important and difficult.''
The new climate already has reshaped the civil liberties organizaton, which once focused on winning its cases in courts but is increasingly turning to the political arena. The group has even taken a page out of the New Right handbook by going directly to the ''grass-roots'' to try to build local support.
''We are learning that the definitions of liberty are fought out in the political arena,'' says Shattuck. ''It is not enough to rely on decisions of the courts unless there is popular support for the courts.'' As part of the new strategy, the ACLU is running conferences around the country with the theme ''campaign to defend the Bill of Rights in Congress.''
Shattuck lists six areas his group considers most pressing:
1. Extending the Voting Rights Act. The law, which protects the rights of minorities to vote, has strong ACLU backing. The House already has voted for extension. President Reagan late last week gave a lukewarm endorsement of the act, but encouraged the Senate to add ''reasonable'' procedures to allow states and localities to bail out of the Voting Rights Act requirements.
2. Protecting the federal courts. Shattuck has counted some 40 bills in Congress aimed at stripping the federal courts of authority to rule on cases involving abortion, school prayer, and school busing. He calls these bills a dangerous precedent for amending the Constitution by a simple act of Congress, short-circuiting the amendment process.
3. Reproductive freedom. While the Supreme Court ruling that granted abortion rights in 1973 was correct, Shattuck says, ''There was not enough political support for it when it came down. Perhaps the way wasn't paved.'' He is lobbying against several attempts to overturn that decision, including a Senate bill that would give legal personhood to a fetus.
4. Criminal justice changes. He is opposing a number of Reagan proposals, including jailing accused criminals without bail if they are considered dangerous, permitting use in court of some evidence gained illegally, and limiting a prison inmate's access to federal courts.
5. Internal security. Included is an effort to halt a Reagan administration bill to exempt much of the Federal Bureau of Investigation and Central Intelligence Agency files from being released to the public through the Freedom of Information Act.
A recently leaked administration proposal to allow the CIA to infiltrate groups in the US would open the door to civil liberties abuses, says Shattuck, who applauded the Republican-controlled Senate Intelligence Committee for its Oct. 27 action urging the President not to adopt the new guidelines.
6. Immigration law. The ACLU is seeking to halt an administration effort to streamline exclusion and asylum hearings for aliens as well as a plan to penalize employers who hire illegal aliens.
During the coming months on Capitol Hill, Shattuck and his staff of five will be testifying at congressional hearings, cornering members, and providing thick studies giving the ACLU viewpoint. Members may not be moved by the number of ACLU voters in their districts, since there are only 250,000 members nationwide. But according to Shattuck, ''They know we have access to virtually every editorial writer on the major newspapers. We participate in the molding of public opinion.''
''I'm very optimistic,'' says the ACLU Washington chief. ''I believe there's a battle going on right now for the Bill of Rights and we're going to come out on the other side with much of it intact.''
Lobbying will not change the fact that the present Department of Justice has changed the landscape in its civil rights division, he adds, ''but I believe that we will be able to protect the courts.''