PRESIDENT REAGAN made a special stop in flood-stricken Fort Wayne last March, visited with worried citizens and even hoisted a sandbag onto a makeshift dike. Did this stop the floods? No. But it sent to the people of Fort Wayne a message of personal and national concern. Moreover, his symbolic gesture was followed by effective action. Returning to the capital, the president declared Fort Wayne a major disaster area and sent federal funds to the area for flood relief and reconstruction.

On Tuesday, the president made another gesture. He and Mrs. Reagan visited the home of Barbara and Phillip Butler, victims of a Ku Klux Klan cross burning when they moved into their Prince George's County home in 1976. The president said he had been shocked to read about the incident in the morning paper and had told his advisers he wanted to assure the Butlers personally that cross burning "is not something that should have happened in America."

He spoke, as a president uniquely can, for us all. A single presidential visit to a black family does not end racism in America. But the president's gesture certainly conveyed his concern about racial violence and expressed the national outrage on the subject. Is it possible that the visit also was meant to signal a new administration sensitivity to problems of minorities? If so, we look now for action to follow the symbolic gesture, as it did in Fort Wayne.

When he returned to the White House after his visit to the Butlers', the president issued a ringing endorsement of Sen. Dole's voting rights compromise, and within 24 hours the bill was reported by the Senate Judiciary Committee on a vote of 17-1. That's a very good start.

But to address more directly the problems experienced by the Butlers when they tried to buy a home in a predominantly white community, Mr. Reagan should reaffirm his commitment to enforce federal fair housing laws. Meanwhile, his administration should encourage the peaceful integration of residential neighborhoods, which is the most effective alternative to the kind of school busing he opposes. If Tuesday's visit indicates a change of emphasis that will be reflected more broadly in government policy, it will be doubly welcome.