Mike Pence will be president 'soon' if Trump fires Robert Mueller: Ex-Bush lawyer
President Donald J. Trump and Vice President Mike Pence at the Pentagon in Washington, D.C., Jan. 27, 2017. (DOD photo by U.S. Air Force Staff Sgt. Jette Carr)

A former ethics lawyer to President George W. Bush warned on Twitter Saturday that if President Donald Trump follows the advice of Fox News and fires Special Counsel Robert Mueller, then we should expect to "soon" be calling Mike Pence "Mr. President."

TheHill.com reported that former White House counsel Richard Painter made the prediction after appearing on Fox.

"Just appeared on FOX News. They are building a case for firing Mueller. If that happens Mike Pence will soon become the 46th President," wrote Painter.

Trump launched an attack on Deputy Attorney General Rod Rosenstein this week, accusing Rosenstein of leading a "witch hunt" against him. The president is reportedly "obsessed" with media coverage of the investigations against him and is acting increasingly erratic and agitated in meetings with aides, blurting out, "I'm not under investigation!" abruptly during conversations.