SPRINGFIELD -- Thousands converged on the nation's capitol Thursday to mark the 36th anniversary of Roe versus Wade. But anti-abortion supporters are already looking ahead toward what could be their first big legislative battle.

Much has been made of President Obama's reversal of an executive order that banned abortion funding for non-governmental groups working outside the U.S. But abortion opponents already have their sights set on another piece of legislation, called FOCA. That's short for Freedom of Choice Act (FOCA).

First introduced in 2007, FOCA is meant to protect a woman's right to begin, prevent or continue a pregnancy. Anti-abortion groups are worried about it because President Obama has said he would sign the bill into law.

What would FOCA mean locally?  Since it would be a federal law, it could override any state restrictions on abortion and secure a woman's right to choose. But the Catholic Church fears it could overturn protections for Catholic hospitals, like St. John's -- that don't want to perform abortions.

The Bishop of the Springfield-Cape Girardeau Diocese was among the marchers in Washington today, but his director said this policy could impact a Catholic hospital like St. John's.

"If we were to have FOCA then it would be possible that down the line, the legislature might say, or a court may rule, that if an institution isn't willing to offer abortions, then their ability to benefit from Medicaid or Medicare funds would be restricted," said Dr. Don Emge of the Springfield-Cape Girardeau Catholic Diocese.

St. John's spokesperson Cora Scott said the hospital supports the Catholic Church's position, which is opposition to FOCA.  But a spokesperson for Planned Parenthood Missouri says FOCA has nothing to do with imposing requirements on hospitals to perform abortions.

For more on the Catholic church's position on FOCA, click HERE.

For more on Planned Parenthood's position, click HERE.