Don't want to get all conspiracy but..

On top of lobbyist cash... Were any of the votes obtained through blackmail?

http://www.latimes.com/news/opinion/la-op-sanchez16mar16,0,4039194.story

Without meaningful oversight, presidents and intelligence agencies can -- and repeatedly have -- abused their surveillance authority to spy on political enemies and dissenters.

The original FISA law was passed in 1978 after a thorough congressional investigation headed by Sen. Frank Church (D-Idaho) revealed that for decades, intelligence analysts -- and the presidents they served -- had spied on the letters and phone conversations of union chiefs, civil rights leaders, journalists, antiwar activists, lobbyists, members of Congress, Supreme Court justices -- even Eleanor Roosevelt and the Rev. Martin Luther King Jr. The Church Committee reports painstakingly documented how the information obtained was often "collected and disseminated in order to serve the purely political interests of an intelligence agency or the administration, and to influence social policy and political action."

Political abuse of electronic surveillance goes back at least as far as the Teapot Dome scandal that roiled the Warren G. Harding administration in the early 1920s. When Atty. Gen. Harry Daugherty stood accused of shielding corrupt Cabinet officials, his friend FBI Director William Burns went after Sen. Burton Wheeler, the fiery Montana progressive who helped spearhead the investigation of the scandal. FBI agents tapped Wheeler's phone, read his mail and broke into his office. Wheeler was indicted on trumped-up charges by a Montana grand jury, and though he was ultimately cleared, the FBI became more adept in later years at exploiting private information to blackmail or ruin troublesome public figures. (As New York Gov. Eliot Spitzer can attest, a single wiretap is all it takes to torpedo a political career.)