THE SURGE of First Amendment cases now before various federal courts and regulatory agencies suggests a disquieting pattern. It shows the federal government pressing, increasingly aggressively, into areas that until now have been well beyond its constitutional limits. Federal judges are becoming increasingly receptive to these incursions, and willing to subject the freedom of expression to routine commercial regulation.

In recent weeks we have discussed, one by one, some of these cases in this space. Let's draw them together.

The Securities and Exchange Commission is now pursuing several cases in which it hopes to establish its authority to regulate the financial press. There is a difference of opinion here between the SEC and this newspaper. The SEC protests that it is attempting neither to regulate nor to license publishers and writers. But, we note, it is asserting a power and a responsibility to set standards of moral character for those people who are to be permitted to publish in financial fields. After all, the commission asks, you wouldn't want crooks putting out newsletters for people to read, would you? It further claims the authority to oversee what goes into the financial press, and why, and whether writers or editors had any hidden interests in saying what they did. If a publication doesn't measure up to the SEC's rules, the SEC tells it to stop publishing. That is known as a prior restraint, and until very recently American law has held it to be flatly unconstitutional. Now it seems to be in question.

Christopher L. Lowe, who puts out a New York newsletter, has challenged an SEC order to stop publishing. An appellate court upheld the SEC since, in its view, publishing a financial newsletter is a commercial activity subject to normal commercial regulation and, in any event, the newsletter is "commercial speech." Commercial speech is a concept invented to enable the government to step around the Constitution and regulate advertising. But now, according to this decision, it seems to include anything written on a commercial subject.

The CIA's attack on the American Broadcasting Company is even more startling. In a news broadcast, ABC had suggested that the CIA tried to arrange the murder of a Honolulu financial figure. The CIA denied it vehemently, and, after a rather long delay, ABC acknowledged on the air that its source could provide no supporting evidence. But the CIA proceeded to file a complaint with the Federal Communications Commission demanding that the FCC hold its own investigation and take the results into account when ABC's broadcasting licenses came up for renewal. Is defamation of a government agency now punishable by regulatory retaliation?

And then there's the federal grad jury in Philadelphia that has subpoenaed the notes and papers of an author named Antoni Gronowicz, who wrote a book about Pope John Paul II. The interesting point here is that the judge didn't see any First Amendment question at all when Mr. Gronowicz refused to comply, and held him in contempt. The appeal is to be argued next month.

Through all of these cases there runs one thought. These government agencies and these judges are saying: If we don't protect the truth, who will? For two centuries in this country, the answer has been that truth is best left to the clash of controversy -- and nothing needs to be protected but the freedom to engage in it. If a statement seems wrong, it can be challenged. Some assertions stand up to challenge. Others collapse, like ABC's murder story, with damage to the reputations of the people who broadcast it. That is the proper penalty for error in these cases.

But within the government, and here and there in the courts, faith in the free market of news and ideas seems to be declining. The hunger to regulate that market is on the rise.