In House of Cards Season 5, Garrett Walker makes a return, and the story surrounding his removal from office again becomes relevant to the storyline. But this happened three full seasons ago, so for those who have forgotten the details, here’s a quick recap of how Frank Underwood betrayed Garrett Walker and became president.
Walker’s downfall revolved around a man named Raymond Tusk, a billionaire industrialist. He had been donating money to the Democratic party via a Super PAC, but it turned out that this was money that had been illegally laundered through a casino.
It’s implied in the show that none of the Democrats knew that the money they were receiving from Tusk was not legal. But Raymond Tusk in Season 2 lied before the House Oversight Committee, saying that Walker was in on the whole thing and knew that the Super PAC funds were illegal.
Why did he do that? Well, he made a deal with Frank Underwood whereby Underwood would pardon Tusk when he got into office in exchange for Tusk ensuring Walker’s downfall.
There were a few other reasons for Walker’s resignation, including the fact that Walker was having marriage problems, and it came out that he had been prescribed medication; Walker’s political opponents then started accusing him of having his judgement impaired throughout the entire length of his presidency.
Walker was not actually impeached, though. Rather, he was facing a likely impeachment, and so he resigned voluntarily, similar to what happened with Richard Nixon in real life. Frank Underwood subsequently took office and pardoned both Raymond Tusk and Garrett Walker.
In Season 4, Walker speaks with Tom Hammerschmidt, saying that he wanted to go public and say that Raymond Tusk lied, but he knew that as soon as he got the pardon, nobody would believe him. Still, he ended up going on the record and speaking with Tom Hammerschmidt for a story, and so Season 4 ends with an article being published which alleges that Frank Underwood conspired to have Garrett Walker impeached and made a deal with Raymond Tusk. Of course, we as the viewer know this to be completely accurate, and that revelation threatens to destroy his presidency.