Below are portions of several articles. I omitted most of the partisan fluff as able. I've been trying to get up to speed on this but several things stand out. I'm not convicting nor exonerating anyone, but I don't think we can categorically say any of the players involved are without guilt. We will have to wait to find out what the FISA investigation reveals and if they pursue Trump. Additionally, nothing I've read from multiple articles say Obama or certain members of his DOJ are in the clear on this either. We still don't know enough. And per usual, someone had to be the first to tell everything they know and revealed Trump's name in a FISA investigation which, as noted in one of the articles below, is a felony:
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.
Under the FISA process, it is technically the FISA court that orders surveillance. And by statute, it is the Justice Department, not the White House, that represents the government in proceedings before the FISA court. So, the issue is not whether Obama or some member of his White House staff ordered surveillance of Trump and his associates. The issues are (a) whether the Obama Justice Department sought such surveillance authorization from the FISA court, and (b) whether, if the Justice Department did that, the White House was aware of or complicit in the decision to do so.
FISA national-security investigations are not like criminal investigations. They are more like covert intelligence operations which presidents personally sign off on. The intention is not to build a criminal case; it is to gather information about what foreign powers are up, particularly on U.S. soil. One of the points in FISA proceedings being classified is that they remain secret the idea is not to prejudice an American citizen with publication of the fact that he has been subjected to surveillance even though he is not alleged to have engaged in criminal wrongdoing.
To be clear, there does not seem to be any evidence to suggest that any surveillance or requests to conduct surveillance against then-candidate Donald Trump was done outside the FISA process. Nevertheless, whether done inside or outside the FISA process, it would be a scandal of Watergate dimension if a presidential administration sought to conduct, or did conduct, national-security surveillance against the presidential candidate of the opposition party. Unless there was some powerful evidence that the candidate was actually acting as an agent of a foreign power, such activity would amount to a pretextual use of national-security power for political purposes. That is the kind of abuse that led to Richard Nixons resignation in lieu of impeachment.
The original FISA request which specifically named and broadly targeted Donald Trump was denied, a second request was redrafted months later which narrowed down on equipment in Trump Tower. The second request is said to have been granted, despite the fact that FBI sources did not believe these servers to be of actual national security or possess any illegal ties to Russia. The notion that this second FISA warrant was granted is highly significant as they exist to investigate cases when Foreign Intelligence is suspected of operations in the US.