Speaking before he addressed a group of Democratic lawyers in Houston Thursday, David Cay Johnston, one of President Donald Trump’s biographers, said that he did not know which senior official penned The New York Times‘ anonymous opinion piece that indicated there is a resistance within the White House that has been blocking Trump from taking actions that are not in the interest of the country.

“But when this is all over, some of the people [working in the administration] who have been chastised in public will be heroes,” he said.

Johnston, a Pulitzer Prize-winning journalist who has written about Trump for 30 years, spoke about Trump, the Constitution, and impeachment to the Harris County Democratic Lawyers Association Thursday. In his talk, he said he expects the president will fight back against the Russia probe after the midterm elections, and that job security isn’t looking good for U.S. Attorney General Jeff Sessions or Special Counsel Robert Mueller.

“He will fire Sessions. He will have his toady [a successor to Sessions] fire Mueller,” Johnston said, adding that he expects this will happen regardless of whether the Republicans maintain control of Congress after the midterms.

But Johnston warned that if the Republicans do keep even a small margin in the House of Representatives, the “Trump people” will move full speed ahead to reshape the judiciary, to deconstruct government even more, and to use tactics such as suppressing voting rights.

He said there will be violence, possibly against journalists, in the wake of Trump’s inflammatory remarks against reporters and his constant labeling of journalists as the “enemy of the people.”

Johnston and Houston lawyer Barbara Ann Radnofsky, who wrote the book “A Citizen’s Guide to Impeachment,” participated in the panel discussion about Trump and the U.S. Constitution, a document that Johnston said Trump does not understand.

Johnston told the group of Democratic lawyers that it will be interesting to see if Democrats regain control of the House and move forward with impeaching Trump. Radnofsky, a retired partner with Vinson & Elkins in Houston who currently has a mediation practice, said impeachment is a good process, but it can be a slow one.

“It could last the duration of the presidency,” she said.

In addition to the anonymous Times op-ed piece, excerpts from Bob Woodward’s new book, ”Fear: Trump in the White House,” have been published this week, raising more questions about Trump’s effectiveness and fitness for office.

Johnston is the author of “The Making of Donald Trump,” published in 2016. His latest book is titled “It’s Even Worse Than You Think: What the Trump Administration is Doing to America.”