"President Trump’s early Saturday morning tweeting has exploded to the forefront an uncovered scandal I’ve been talking about since early January (including in this weekend’s column): The fact that the Obama Justice Department and the FBI investigated associates of Donald Trump, and likely Trump himself, in the heat of the presidential campaign.
To summarize, reporting indicates that, prior to June 2016, the Obama Justice Department and FBI considered a criminal investigation of Trump associates, and perhaps Trump himself, based on concerns about connections to Russian financial institutions. Preliminary poking around indicated that there was nothing criminal involved. Rather than shut the case down, though, the Obama Justice Department converted it into a national-security investigation under the Foreign Intelligence Surveillance Act (FISA). FISA allows the government, if it gets court permission, to conduct electronic surveillance (which could include wiretapping, monitoring of e-mail, and the like) against those it alleges are “agents of a foreign power.” FISA applications and the evidence garnered from them are classified – i.e., we would not know about any of this unless someone had leaked classified information to the media, a felony."