The Supreme Court agreed yesterday to decide whether the Constitution forbids dominant political parties from redrawing election districts to their own advantage.

The court said in its 1964 one-man, one-vote ruling that it was unconstitutional for the number of voters in each district to vary widely. But the court never has said whether the Constitution forbids one political party from "discriminating" against another.

With Justice Lewis F. Powell on the bench for the first time since his prostate surgery in early January, the court also took the unprecedented step of ordering re-arguments next month in three of the 56 cases argued in his absence.

The action could mean that the justices were closely divided in those cases and needed or wanted Powell's views.

In the elections case, a three-judge federal panel ruled last December that Indiana Republicans unconstitutionally "gerrymandered" or politically rigged voting lines for the 1982 state legislative elections.

The panel majority said the Republicans had divided towns and communities to reduce the Democrats' chances at the polls. That, the panel said, was a violation of the Democrats' rights to equal protection under the Fourteenth Amendment.

Although Indiana Democrats won that case, the same reasoning could mean victory for California Republicans engaged in a similar battle of "ins" versus "outs."

The Democratic-controlled California General Assembly has filed a "friend-of-the-court" brief in the Indiana case on the side of the Republicans. The California Democrats argued that courts should stay out of controversies involving political gerrymandering.

In the Indiana case, the appeals panel said that while Democratic candidates for the state House got 52 percent of the vote in 1982, they won only 43 percent of the seats.

That reasoning gave Democrats a victory in Indiana, but could spell victory for Republicans in other states, including California, where Republicans have complained for years about Democratic gerrymandering of suburbs to weaken growing GOP power there.

The California Republicans also have sued, but the high court, without comment, yesterday turned down their appeal of a federal appeals court ruling last November. That ruling said the Republicans first should resolve some state law issues in state court before returning to the federal court.

The Indiana case, Davis v. Bandemer, will be argued here next fall.

The justices also agreed to decide whether privately owned public utility companies may be forced to include messages from other groups as inserts in their monthly billing envelopes.

The court will hear an appeal by the Pacific Gas and Electric Co. in California, where the state public utilities commission required it to insert a fund-raising message for a consumer group.

The court ruled in 1980 that states cannot prohibit public utilities from sending extra material along with monthly bills. But the court never has ruled that states may require utilities to include such material.

Consumer groups in several other states, including New York, Nevada and Oregon, are demanding access to utilities' billing envelopes, while utilities are preparing counter-challenges to such inserts, PG&E said in its appeal.

The California utilities commission found that PG&E had included political information in its billing envelopes. The commission ordered the company to insert a consumer group's messages so long as no additional costs were incurred. The California Supreme Court turned down PG&E's appeal of the order.

In its appeal to the high court, PG&E argued that the order violated the utility's First Amendment rights to communicate with its customers and its right not to publish a message with which it disagrees. The case is Pacific Gas and Electric Company v. Public Utilities Commission of California.

The three cases the court ordered reargued April 22, 23 and 24 are:

* Pattern Makers' v. National Labor Relations Board, which involves the power of unions to prevent members from resigning during or shortly before strikes;

Montana v. Blackfeet Tribe of Indians, which involves state taxation of oil and gas taken from Indian lands;

Massachusetts Mutual Life Insurance Co. v. Russell, which involves whether an employer can be held responsible for improper processing of disability claims.

Eugene Gressman, a law professor and court expert, said he could recall no instance in the last 42 years in which the court heard reargument in even one case in the same year unless the justices wanted a new issue discussed. The court yesterday did not ask the lawyers to discuss new issues in their reargument.

There is no rule that says Powell could not vote in those cases without hearing oral argument or listening to a tape of the argument, Gressman said, but Powell may prefer to hear the arguments firsthand.

Even with the reargued cases, the court has four hours unfilled on its April calendar.