Devastating: numerous democrats and some republicans are sent to prison. Certain foreign allies are also implicated. American citizens lose even more faith in the ability of our government to function fairly. Television and newspaper news is ruined forever. This has a profound effect on young voters. Instead of finding trust in the republican party, they instead turn to third party alternates, mostly violent far-left organizations. America is forever changed. Conservatives feeling of satisfaction turns sour when they realize that the very fabric of the nation has been damaged for good.
Justice: Clinton, McCabe, Brennan and a relatively small set of Obama administration officials go to prison. CNN/MSNBC/NYT/WaPo go out of business. Democrats lose 2020 elections very badly in a manner much worse than the damage Nixon did to the GOP. The Green party becomes the party that leftists support and the democrat party dies a slow death. Safeguards are put into place, such as FISA court oversight, that will make abuse of government difficult.
Likely: Congressional hearings will be held. Only McCabe and Brennan are indicted, but serve no time. Voters are tired of the whole thing. The GOP wins easily in 2020, but the Democrat party is fully intact. Some safeguards are put into place, but many loopholes remain.