Sen. Jeff Flake has been one of President Trump’s strongest critics, both when it comes to behavior and certain policies — such as trade. And the president has responded by threatening to put millions toward defeating Flake in the 2018 GOP primary as the senator runs for re-election.

Flake’s latest public move will put him even more prominently in Trump’s crosshairs.

On Tuesday, Flake’s book "Conscience of a Conservative" will be published. Many of its pages are devoted to criticizing the president.

Arizona Republic columnist Bob Robb got one of the early copies of the book, read it, and is with me to talk about it.