WASHINGTON (AP) – Both sides in the abortion rights dispute are mobilizing to battle for the state legislatures that will decide the highly charged issue if the Supreme Court, reshaped by Ronald Reagan, retreats from the 1973 decision legalizing abortions.

“We are the majority,” proclaimed Molly Yard, president of the National Organization for Women after a rally Sunday sponsored by abortion rights activists attracted at least 300,000 people to the nation’s capital.

But opponents of abortion point as signs of their political strength to their election victories, particularly in 1978, and 1980, and to their strength in state legislatures.

Both sides are aniticipating that the high court, made more conservative with Reagan’s three appointments, will by early July allow states to place some restrictions on abortion.

Arguments in the Missuori case will be heard April 26. The ruling could significantly alter the court’s 1973 Roe vs. Wade decision, which gave women the right to an abortion.

If the justices, as expected, restore to the states some powers to regulate abortions, the high-stakes battles for state legislative control could have a profound impact on the ongoing battle to control the redrawing of House districts to confrorm to next year’s Census.

The national Republican and Democratic chairmen already have designated reapportionment as their top political priority for the next two years. Republican charirman Lee Atwater contends that Democratic control of a majority of state legislatures has resulted in drawing House district lines that have solidified the chamber’s Democratic majority.

While the controversy over abortion crosses party lines, successes by candidates wanting to make abortion illegal are more likely to benefit Republicans, while those of candidates favoring the right to an abortion tend to favor Democrats.