The professionals in the newspaper business probably had their leads written last night before they went to dinner: "URGENT. Jimmy Carter and Ronald Reagan swept to. . . ."

You know the rest. Carter and Reagan romped in Florida, Georgia and Alabama, just as everyone had predicted before this campaign started getting interesting.

No apparent volatility in the solid South last night, no quick switches at the wire. Just sweet victories for the Republican and Democratic front-runners and little to look forward to for most of the losers.

George Bush lost more than anyone else last night. In Florida he had hoped to be "respectable," and only some of his most devoted followers would pick out that adjective for his showing here. With polls in Illinois showing him third behind John B. Anderson and Ronald Reagan, Bush is in trouble.

About all Edward M. Kennedy can take north with him is the knowledge that the Jews in Florida gave him a majority, an equation he'll try to convert into a statewide victory in New York, assuming that the results from next Tuesday's Illinois primary aren't horrible.

After last night, and with about 28 primaries left to go, the delegate count, according to United Press International, looks like this: Carter 269, Kennedy 139, with 1,666 needed for the nomination. Reagan 165, Bush 45, Anderson 15, uncommitted 17, with 998 needed for the nomination.