Washington Post has an article on Olson that includes his frustration with the Administration regarding anti-terrorism:

In retrospect, it's easy to see why Olson has turned Trump down twice. In addition to his commentary Monday, Olson authored a Fox News op-ed a week ago — right around the time he was being recruited — accusing the Trump administration of “acquiescing in the evisceration of one of America’s most important counter-terrorism laws” — the Anti-Terrorism Act of 1992:

But where is the Trump administration?  In June of last year, the Supreme Court requested that the solicitor general submit the views of the United States as to whether the Court should accept the case for review. This should have been an easy call. As long as we have had solicitors general, it has been recognized that they have a duty to defend the constitutionality of Acts of Congress if there is a reasonable argument to do so. And that duty has maximum force where, as President Obama’s solicitor general wrote, “the statute in question … is a vital part of the Nation’s effort to fight international terrorism.”

Months went by with no answer from the administration. It ultimately took the Trump administration eight months to file its brief. Astonishingly, the brief sided with the PLO and against American victims of terrorism. The administration urged the Supreme Court to leave undisturbed the New York court’s amputation of the Anti-Terrorism Act.

This Administration has managed to piss off some pretty hard core conservatives.