SPARTANBURG, S.C.- Republican presidential candidate John McCain , looking to improve his standing with the party’s conservative voters, said Sunday the court decision that legalized abortion should be overturned.

“I do not support Roe versus Wade. It should be overturned,” the Arizona senator told about 800 people in South Carolina, one of the early voting states.

McCain also vowed that if elected, he would appoint judges who “strictly interpret the Constitution of the United States and do not legislate from the bench.”

The landmark 1973 decision in Roe v. Wade gave women the right to choose an abortion to terminate a pregnancy. The Supreme Court has narrowly upheld the decision, with the presence of an increasing number of more conservative justices on the court raising the possibility that abortion rights would be limited.

Social conservatives are a critical voting bloc in the GOP presidential primaries.

McCain’s campaign also announced early Sunday that he had been endorsed by former Oklahoma Gov. Frank Keating, who had been considering his own bid for the White House, and former Texas Sen. Phil Gramm, who failed in his bid for the Republican nomination in 1996.

Keating told the crowd that McCain is the “only candidate who is a true-blue, Ronald Reagan conservative.”

McCain was scheduled to attend a rally promoting an abstinence program Sunday evening.

McCain has strong name recognition and the largest network of supporters in South Carolina. That backing comes in part from his staunch support for the Iraq war, something on which he focused a day earlier in Iowa. But it’s the same state that dealt a crushing blow to his presidential aspirations in 2000.

McCain is trying to build support among conservatives after a recent rebuke from Christian leader James Dobson, who said he wouldn’t back McCain’s presidential bid. Conservatives question McCain’s opposition to a constitutional amendment to ban gay marriage. He opposes same-sex marriage, but says it should be regulated by the states.