Barack Obama wades back into politics with bold tweet about Obamacare

Former President Barack Obama has spent the first 100 days of the Trump presidency largely out of the public eye, but he waded back into the fray on Tuesday -- sending perhaps his most politically charged tweet since leaving office in defense of his health care law.

Obama defended the law, which Republicans are currently working to repeal and replace, by retweeting a message shared the night before by late night talk show host Jimmy Kimmel.

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On Monday night, Kimmel tweeted a video of his show's monologue where he talked about the birth of his newborn son William, called Billy, who was found to have a congenital heart defect. The unusually personal and political monologue included a direct plug for Obamacare.

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Obama retweeted Kimmel's plea on Tuesday.

"Well said, Jimmy," he wrote. "That's exactly why we fought so hard for the ACA, and why we need to protect it for kids like Billy. And congratulations!"

Obama has remained mostly quiet on political issues since leaving office. He only touched lightly on politics during his first public appearance in Chicago last week. His tweets have avoided the nitty gritty of policy, instead offering condolences to victims of terror attacks, mourning the loss of musical icon Chuck Berry and wishing his wife a happy Valentine's Day.

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He has not mentioned Trump.

But the tweet comes amid Republican leaders' efforts to bring their health care replacement plan to a vote. Trump had originally vowed to see Obamacare repealed and replaced during his first 100 days in office -- a promise he was unable to keep.

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Republicans in Congress are moving toward trying to pass a new version of the repeal legislation this week, but it's unclear whether or not they have the votes to accomplish that goal.