I am sure they had to present some level of evidence to the FISA court to obtain the warrant. One may analyze and comment on the judge that heard the case, but he/she apparently felt there was enough there to approve the warrant. Yet another possible link to Russia. Obviously, it has to be further investigated, and likely will be by the FBI and DOJ. But this is another cloud on the horizon in the Trump-Russia connection investigation.
I do find his commentary to be a bit inflammatory toward the Obama administration;
There have been various reports [about FISA documents and FBI surveillance of him]," Page said. "But I was so happy to hear that further confirmation is now being revealed. It shows how low the Clinton/Obama regime went to destroy our democracy and suppress dissidents who did not fully support their failed foreign policy. It will be interesting to see what comes out when the unjustified basis for those FISA requests are more fully disclosed over time, including potentially the Dodgy Dossier -- a document that clearly is false evidence, which could represent yet another potential crime."
Page was referring to a leaked dossier of unverified information compiled by a former British intelligence official for Trump's political opponents. Then-President-elect Trump and President Barack Obama were briefed on the existence of the dossier before Trump's inauguration, CNN reported.
Odd that he has already reached the conclusion that nobody else seems to have reached, that the Trump Dossier "clearly is false evidence". How in the world does a self-admitted low level adviser know this, praytell?