"Tired of the Jelly Bean Republic?" asks artist Michael Lebron on an anti- Reagan poster he sought to display in Metro subway stations. The photomontage under this headline shows the president and a number of administration officials seated at a table laden with food and drink. The men are laughing, and the president is pointing to the right side of the poster where another picture of poor people and racial minorities is displayed.

Metro officials, who sell advertising to political and advocacy groups, refused to rent space for this poster on the grounds that it was deceptive. The other day, the U.S. Court of Appeals ruled that Metro had violated Mr. Lebron's right to free speech.

This country, the Supreme Court said 20 years ago, has a "profound national commitment to the principle that debate on public issues should be uninhibited, robust and wide-open." Public agencies allocating public space for the expression of political views have a special obligation to protect these rights.

In this case, Judge Robert Bork wrote, it was easy to see why the censorship was unwarranted. The poster was not deceptive at all; it was a straightforward anti-Reagan statement that made no pretext of objectivity. No reasonable person would have thought the scene portrayed was a single photograph: the lighting was different in the two halves of the picture, the figures were not in proportional sizes and the artist even offered to add a disclaimer stating that the scene was a composite of photographs.

But Judge Bork and Judge Antonin Scalia -- two of the court's conservative members -- would have reversed Metro's action on even broader grounds if it had been necessary. Both believe that an agency of a political branch of government cannot impose prior restraint on the publication of a political message even if that message is false. Nothing compels Metro to accept political advertising for subway displays, but once the decision is made to accept some of these statements, public officials cannot pick and choose what messages are acceptable on the basis of subjective judgments of what is "derisive, exaggerated, distorted, disceptive or offensive," as the Metro regulation allowed. That is an interference by the government with a citizen's right to engage in free political discourse. The court's message is clear and it is right.