Story highlights Obama's remarks are his first since the House voted to repeal and replace Obamacare on Thursday

They mark a rare post-presidency appeal on a policy matter for Obama

(CNN) Former President Barack Obama called on members of Congress to oppose the repeal of the Affordable Care Act, his signature health care law, in a speech Sunday night at the John F. Kennedy Library Foundation in Boston.

Obama's remarks, which he gave upon receiving the 2017 John F. Kennedy Profile in Courage Award, are his first since the House voted to repeal and replace Obamacare on Thursday. They mark a rare post-presidency appeal on a policy matter for Obama, who has steered clear of discussing political issues since leaving office.

Obama called on lawmakers to have the courage to "champion the vulnerable and the sick and the infirm." He said he hopes they understand that "courage does not always mean doing what is politically expedient, but what they believe deep in their hearts is right."

The former President also said there was a reason why health care reform had not been accomplished earlier: "It was hard."

In his acceptance speech, Obama talked about the need for courage in times when politics "remains filled with division and discord, and everywhere we see the risk of falling into the refuge of tribe and clan."

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