SEN. PATRICK J. LEAHY (D-Vt.) has responded splendidly to the District's critical request for approval to provide about 8,500 jobs for teen-agers this summer. As chairman of the Senate subcommittee that handles the city's budget, Mr. Leahy went to bat for Mayor Marion Barry's entire summer jobs proposal - including defending it against criticism from Sen. Lawton Chiles (D.-Fla.). Mr. Chiles questioned whether the jobs to be offered would be "meaningful"; Mr. Leahy responded properly that "the mayor deserves an opportunity to at least try it."

Along with Sen. Charles McC. Mathias Jr. (R-Md.), who has been a strong supporter of the city's jobs effort, Sen Leahy impressed upon the subcommittee members the importance of letting the city government do all it can for the teen-agers this summer. He was right, too, to emphasize that private business remains challenged to meet the government's effort: "I would hope . . . that the word goes out very clearly that the private sector has a strong obligation to the youth of this area, and that they do their part."

The go-ahead from Sen. Leahy is an important approval. But the process on Capitol Hill is far from over. Needed, too, is the understanding and leadership of Rep. Charles Wilson (D-Tex.), who is Sen. Leahy's counterpart in the House. While Sen. Leahy still is shepherding his subcommittee's decision through the rest of the Senate's voting, Mr. Wilson will call the shots in the important round in the House. Thoughtful and informed members of Congress should recognize that approval of the summer jobs proposal is not a matter of a government handout or of balancing the federal budget. The District's elected government still has to have permission even to spend its own locally raised revenues for an emergency effort to do something for its teen-agers this summer. Mayor Barry and private businesses, labor and individual citizens deserve the chance to do all they can - right away.