President Carter's order to review the visas of Iranian students has stirred concern -- more over the spirit of the act than its legality -- among some constitutional scholars and civil liberties advocates.

Carter has given assurances that the visa reviews are lawful, in accord with "American fairness [and] the full principles of the American Constitution." Some of the experts believe that while the order is within the boundaries of the Constitution, it nonetheless opens the government to serious challenge.

"This is selective justice and selective enforcement of our laws," said Rep. Don Edwards (D-Calif.), chairman of the House subcommittee on civil and constitutional rights. "It is punitive and unacceptable."

The president may be on sound legal ground, said Gerhard Casper, dean of the law school at the University of Chicago, but "from a moral and political point of view, I considered the step most unfortunate -- it has almost a spirit of vindictiveness to it."

Responding to the takeover of the U.S. Embassy in Tehran, Carter last month ordered the Immigration and Naturalization Service to conduct a prompt review of the status of all the estimated 50,000 Iranian students here. p

During the first two weeks of the review, INS had interviewed about half of the Iranian students. Some 3,600 were ruled deportable because of visa irregularities. Under INS rules, they can be deported.

A hearing is scheduled for today in U.S. District Court on a suit brought by the American Civil Liberties Union and the Confederation of Iranian Students challenging the constitutionally of Carter's action.

Edwards, in a letter to the president, asked that he rescind the order on the ground that its selectivity ran counter to American traditions of fairness and was "calculated primarily to respond to public sentiment."

"If the president had said that all foreign students in the United States have to check in with the immigration service, one could not complain. But when he got selective, I saw it differently. I am concerned because due process is protected by our Constitution," Edwards said.

Edwards and Ira Glasser of New York City, executive director of the ACLU, likened the visa reviews of Iranian students with government internment of Japanese-Americans at the outset of World War II.

Edwards, Glasser and others interviewed noted that federal courts had sanctioned the World War II relocation of Japanese-Americans from the West Coast but said history judged that action harshly.

"Someday most of us will be ashamed of the Iranian action, just as we are ashamed of what happened to the Nisei in World War II," Glasser said. "You can't talk to anyone today without hearing them say it was a terrible thing to do to the Nisei. It is easy to say retrospectively. But the time to be moral about these things is not 20 years from now, but now -- when it is difficult."

Prof. William Van Alstyne of Duke University said he "shared the apprehension" over Carter's move against the students. He added, however, "I don't feel it is rankly unconstitutional.

"But when there is selectivity and a category of those visas are to be reviewed, there is a constitutional odiousness to that review," Van Alstyne said.

Prof. Philip Kurland, another constitutional authority at the University of Chicago, said, "I don't like it, but does that make it unconstituional? There is no court history that says it can't be done."

Kurland said the action against the Iranians was "no more selective" than other recent INS sweeps against Mexican aliens thought to be illegally in this country. He noted that the government argued those sweeps were not arbitrary.

But David Landau, an attorney with ACLU's office in Washington, said the INS review of Iranian student visas and the singling out of those students on campuses amounts to "a very dangerous experiment. The United States is very open and treats everyone equally. That's what this country is all about. The fact they are not citizens is almost a technicality."

Landau added, "We find the president assuming inherent authority to circumvent established procedures. That makes an international crisis a domestic crisis -- almost like the 1960s when national security was used as a reason to move against domestic dissent."

Landau, like others interviewed, commented that the presidential action "set a tone" and affects public reaction. They cited a New Jersey bus company's firing of Iranian employes and a South Carolina technical college's summary suspension of Iranian students as natural outgrowths of that.

Chicago's Casper said he felt Carter's televised press conference last week, on which he reasserted intentions to be fair with the students, was "a tempering" of the situation. But he said, "I just hope the government will carry this out in a humanitarian way."