When President Jefferson arranged for the Louisiana Purchase he assured the Nuns of the Order of St. Ursula that the principles of the Constitution and the government of the United States would be sacred and inviolate for them, and that they would be permitted to govern themselves according to their own voluntary rules without interference from the civil authority. He praised them for their wholesome purpose of training up the younger members in the way they should go, and that his office would protect them. "I salute you, holy sisters, with friendship and respect." Letter to Ursuline Nuns of New Orleans, July 13, 1804.
All Christian churches taught against contraception until about the 1930s, when one by one they followed the lead of the Anglicans. But the Catholic church has never wavered. President Obama knew that when he railroaded the ACA through Congress with no Republican support. It's too bad that President Obama, who has sued Little Sisters of the Poor for not violating their religious beliefs, can't assure 21st century nuns of the same protection of the Constitution and his office that President Jefferson did.