On the 39th anniversary of landmark abortion case Roe v. Wade, President Obama and Republican presidential candidates who hope to challenge him in November spoke for and against the controversial Supreme Court ruling Sunday and Monday.

President Obama released on statement on Sunday defending the Roe v. Wade decision, vowing to protect a woman's right to choose.

We must remember that this Supreme Court decision not only protects a woman's health and reproductive freedom, but also affirms a broader principle: that government should not intrude on private family matters, Obama said in the statement.

Obama added he remains committed to this fundamental constitutional right, but called for the country to be united in our determination to prevent unintended pregnancies and promote adoption.

Mitt Romney, widely considered the front-runner in the race for the GOP nomination, released a dueling statement  that spoke out against the court ruling that legalized abortion.

Today marks the 39th anniversary of one of the darkest moment in Supreme Court history ... The result is millions of lives since that day have been tragically silenced, Romney said in a statement on his website.

On Monday, rival Republican hopeful Rick Santorum reaffirmed his commitment to overturn Roe v. Wade in a Wall Street Journal editorial and criticized Mitt Romney and other candidates for not doing enough.

I know life begins at conception. I know that every person, every child conceived in the womb, has a right to life, wrote the former Pennsylvania senator, who has based much of his campaign on his social conservatism.

This anniversary is both a day of sadness for the more than 40 million babies who have been killed since Roe v. Wade.

Santorum, who calls the Supreme Court ruling a violation of the 14th amendment, wrote that Romney's passion for life was apparently overwhelmed by Democrats and was intimidated when he put Planned Parenthood on the advisory board for his Massachusetts health care plan.

Ron Paul and Newt Gingrich did not release official statements on the court ruling's 39th anniversary, but both have called for its repeal.

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