In one of those fine ironies that seen to flourish in periods of governmental transition, a leading candidate for the California Supreme Court Seat that would be vacated by President Reagan's nominee for deputy secretary of state is none other than former president Carter's deputy secretary of state.

Justice William P. Clark, nominated last week for the No. 2 spot at the State Department, could be replaced by Warren Christopher, a Californian who had strong support in the state even before his role in the release of the U.S. hostages made him a minor American hero.

It is also within the realm of possibility that a second vacancy on the California Supreme Court, created two weeks ago by the death of Justice Wiley Manuel, could be filled by Carter's education secretary, Shirley Huftstedler, who was a judge on the 9th U.S. Circuit Court of Appeals in California before joining the Carter administration. Among her supporters is Sen. Alan Cranston (D-Calif).

Both Christoper and Hufstedler are considered good bets for appointment to the court by Gov. Edmund G. (Jerry) Brown Jr., despite comments from Lt. Gov. Mike Curb that he believed Reagan had "taken a number of steps" to ensure Clark would be replaced with a conservative.

In any case, the two vacancies offer Brown the chance to appoint a majority of the seven-member court. Chief justice Rose Bird and Justice Frank Newman are his appointees. Justices Mathew Tobriner and Stanley Mosk were appointed by his father, former governor Edmund G. (Pat) Brown Sr., and Justice Frank Richardson was appointed by Reagan.