Clearly there was surveillance of the Trump campaign, and for good reason. This is a man who publicly encouraged the Russians to violate our laws and hack into email systems. And he claimed many times to love WikiLeaks, an organization whose entire purpose is leaking secret documents. That alone justifies keeping an eye out for problems. There is an issue if this went beyond surveillance into either supplying information to political opponents, or sabotaging the campaign. I think it may be wise to make sure that didn't happen.