You never know whom you'll run into or what you will learn coming back from the Kentucky Derby. As for me, as I returned Tuesday morning, one of the most high-profile of liberal Republicans was on the same flight to Reagan National Airport in Washington, D.C., from Louisville, Ky., where we had both taken in the 131st running of the Kentucky Derby and all the associated events this past weekend. But former Massachusetts Gov. William Weld and I didn't discuss the race or longshot Derby winner Giacomo. Instead, we talked about the President's nomination of John Bolton to be U.S. Ambassador to the United Nations. Weld's background as a liberal Republican and Bolton's conservative credentials notwithstanding, the former Bay State governor is strongly for Bolton's going to the UN. "I worked closely with John at the Department of Justice, where we were assistant attorneys general together," recalled Weld, who headed up the Criminal Division at Justice in the Reagan Administration while Bolton was assistant attorney general for legal counsel. "He's highly intelligent. He's strong medicine, all right, but sometimes strong medicine is needed, such as it is at the United Nations today." Weld, who is an investment banker in New York City these days, also dismissed charges of ugly Bolton behavior toward subordinates, one of the chief arguments used against him. Following his six years as governor, Republican Weld was named U.S. ambassador to Mexico by Democratic President Bill Clinton in 1996. But as a result of the refusal of Chairman Jesse Helms (R.-N.C.) to hold hearings on the nomination before the Senate Foreign Relations Committee, Weld was never confirmed for the diplomatic post and eventually withdrew his nomination. In the wake of escalating attacks on Bolton, Weld last month joined with such conservative veterans of the Justice Department as former Atty. Gen. Ed Meese and former Associate U.S. Attorney General (and past Oklahoma Gov.) Frank Keating to sign a letter in support of the embattled nominee. The 32 Justice Department veterans, all of whom worked closely with Bolton, denounced the "character assassination" of their former colleague in a strongly-worded letter.