Former U.N. ambassador Jeane Kirkpatrick, adept at splitting the hairs that separate authoritarian autocrats from totalitarian autocrats, has discerned a new friend in the Iraqi ambassador to the United States, Nizar Hamdoon. Since last spring, when he became Iraq's first ambassador here following our resumption of diplomatic relations, Hamdoon has worked hard at burnishing Iraq's image; his efforts, sources say, will pay off in a dinner he is giving May 9, which Kirkpatrick will attend as guest of honor.

A spokesman for the embassy described it as a seated dinner for 18. No special occasion, except that the ambassador is "a big fan" of Kirkpatrick's. L'Etat, C'est Moi . . .

Wednesday evening, after the Senate cast votes toward a fiscal 1987 budget that ran dramatically counter to President Reagan's budget recommendations, the "MacNeil/Lehrer Newshour" featured an illuminating debate with White House Budget Director James C. Miller III and Senate Budget Committee Chairman Pete V. Domenici (R-N.M.).

When questioner Jim Lehrer brought the discussion around to the topic of a tax hike, the ubiquitous shade of former budget director David A. Stockman came up, inspiring the following exchange:

Lehrer: "Are you the least bit concerned about the fact that Stockman was in the same situation with Domenici four years ago, and he now says, 'I should have listened to Domenici, Domenici was right and I was wrong?' "

Miller: "It's Miller time." Misnomer . . .

Clarence Thomas, the low-key chairman of the Equal Employment Opportunity Commission, is getting a little tired of being mistaken for the volatile "other Clarence" -- Clarence M. Pendleton Jr., chairman of the Civil Rights Commission.

The two names and agencies are routinely reversed in newspaper editorials and television shows, Thomas said Wednesday in an interview with a small group of reporters. "They're just interchangeable -- like spare parts," he complained.

Pendleton is known for quips that insult his ideological opponents. While it is true that the two Clarences, both black, share opposition to goals and timetables as a way of hiring and promoting minorities and women, Thomas resents anyone "intentionally or carelessly" confusing their styles. Thomas describes his own as "bor-r-ring." Naval Gazing . . .

President Reagan is expected soon to name one of these three as the new Chief of Naval Operations: Vice Adm. Frank B. Kelso Jr., who commanded the battle group that bombed Libya; Adm. Carlisle A.H. Trost, commander of the Atlantic Fleet; or Adm. Ronald J. Hays, Pacific commander. Navy insiders say Secretary of the Navy John F. Lehman Jr. has been pushing for Kelso, and that Defense Secretary Caspar W. Weinberger was cool to that choice after meeting with the admiral just before the Navy's Gulf of Sidra operation, but has warmed to the idea. The one selected will replace Adm. James D. Watkins this summer. A Big Welcome . . .

Sen. David F. Durenberger (R-Minn.) has created something of a fuss in his home state by sending a letter to the State Department requesting that Laotian Hmong refugees not be settled in Minnesota unless they have family ties there. The Hmong tribesmen aided U.S. forces during the Vietnam war.

The letter, written last month and disclosed in a Minneapolis Star and Tribune story yesterday, said the refugees "have proved economically difficult to assimilate. The prognosis for employability among the adult population is very poor." Minnesota has about 10,000 Hmong refugees, one of the highest concentrations in the United States, and about 60 percent receive public assistance, the newspaper reported.

Durenberger aide Jon Schroeder said the letter's purpose was to inquire on behalf of local officials about a rumored large influx of refugees. But Minneapolis Mayor Donald Fraser, a Democrat, said his city did not share the opinions expressed in Durenberger's letter, and an aide to Gov. Rudy Perpich (D) said Perpich would oppose attempts to discourage Hmong resettlement in the state. Shifting to USDA . . .

Christopher Hicks, now director of the White House office of administration and deputy assistant to the president, will be nominated as Agriculture Department general counsel, it was announced yesterday. Hicks, 35, moved to the White House when Donald T. Regan shifted from treasury secretary to Reagan's chief of staff. Hicks had been Regan's executive assistant at Treasury.