Let’s begin in the realm of the fanciful.
Assume, for the sake of argument, that powerful, connected people in the intelligence community and in politics worried that a wildcard Trump presidency, unlike another Clinton or Bush, might expose a decade-plus of questionable practices. Disrupt long-established money channels. Reveal secret machinations that could arguably land some people in prison.
He would have to be marginalized at every turn. Strategies would encompass politics, the courts, opposition research and the media. He’d have to become mired in lawsuits, distracted by allegations, riddled with calls for impeachment, hounded by investigations. His election must be portrayed as the illegitimate result of a criminal or un-American conspiracy.
To accomplish this, bad actors in the intel community could step up use of surveillance tools as a weapon to look for dirt on Trump before his inauguration. They could rely on dubious political opposition research to secretly argue for wiretaps, plant one or more spies in the Trump campaign, then leak to the press a mix of true and false stories to create a sense of chaos.
-- Sharyl Attkisson, "What would the intelligence community's 'insurance policy' against Trump look like?" (THE HILL).