Hill Democrats won't be able to point to Chief Justice Warren E. Burger if President Reagan appoints only hardliners to the new U.S. Sentencing Commission.

Although the chief justice is a solid conservative, the word is that he followed Congress' wishes and sent Reagan the names of a dozen candidates from all parts of the judicial spectrum.

Reagan, while not legally bound to do so, is expected to pick three from that group to sit on the seven-member commission, which was established last year to overhaul federal sentencing laws.

The remaining four members probably will come from a list to be submitted by the Justice Department, where Deputy Associate Attorney General Jay B. Stephens has been scouring the prosecutorial and defense establishments and elsewhere for candidates.

Burger, although still unhappy that the judges who serve on the commission will have to leave the bench temporarily, got at least one change in the legislation: The judicial members can be semi-retired senior judges, who often carry reduced caseloads.

Burger's list includes three semi-retired senior judges and nine active judges, although two will be eligible for senior status by next year.

Burger's picks range from 1st Circuit Judge Stephen Breyer, a liberal former aide to Sen. Edward M. Kennedy (D-Mass.), to conservative William W. Wilkins, a district judge in South Carolina who is a former aide to Sen. Strom Thurmond (R-S.C.).

Others on the list: D.C. Senior Circuit Judge George E. MacKinnon; Thomas A. Flannery and John Lewis Smith, both District Court judges here; U.S. Senior Circuit Judge Reynaldo G. Garza from Brownsville, Tex.; and district judges Hugh Dillon of Indiana, George N. Leighton of Illinois, James M. Byrnes of Oregon, Warren K. Urbom of Nebraska, Leland C. Nielson of California and Earl H. Carroll of Arizona. THANKS, BUT NO THANKS. . . Spring -- or something -- was definitely in the air last week as the Supreme Court sifted through its list of appeals, looking for cases that merited its attention.

For example, there was the appeal by a decorated Army combat pilot who was fired by Eastern Airlines after a sex-change operation.

After Kenneth F. Ulane became Karen F. Ulane in a 1979 operation, the Federal Aviation Administration -- following physical and psychiatric examinations -- recertified her to fly.

Eastern nevertheless would not let her fly, saying she never disclosed her psychiatric history or that she took hormones, which the airline said could be dangerous.

Ulane sued, arguing that she was discriminated against because of her transexuality. A District Court judge agreed, but an appeals panel overruled the finding, saying civil rights laws did not cover transsexuals. Ulane wanted the justices to take her case. They declined.

Then there was the pigeon-racing brouhaha in Pelham Manor, N.Y.

The city fathers, backed by a local judge, said zoning laws barred Diane B. Crea from keeping pigeon coops at her home.

Crea, fined $500 for keeping the birds in two garages, appealed to the justices, arguing that the zoning ordinance is unconstitutional. The justices turned their backs.

Finally, there was The Ecclesiastical Order of the Ism of Am Inc., a religious group incorporated in Michigan in 1978. For $25, one can be ordained a minister in the Ism of Am and get a key ring, a ministry certificate and instructions on performing civil wedding ceremonies.

Additional contributions entitle ministers to pamphlets that the government said discussed the tax benefits of being a minister.

The Internal Revenue Service refused to grant the group tax-exempt status. The Ism of Am appealed, saying it had been discriminated against because it is not a traditional church but "a deistic religion that favors the teachings of Thomas Paine."

The justices looked at the case -- and said no thanks.