Sen. Mark Kirk (R-Ill.) suffered a massive stroke in 2012. He had to relearn how to walk, write and speak. It took him nearly a year before he was able to return to the Senate. He suffered permanent paralysis on his left side and used a cane and wheelchair. The stroke left him with halting speech — and in 2016, USA Today reported that he “blurted out a series of gaffes last year that he later walked back, leading some to question if his stroke was to blame.”