Wisconsin Gov. Scott Walker is set to drop out of the presidential race Monday night, a source close to the campaign confirms to NBC News.
He is scheduled to hold a press conference in Madison, Wisconsin, at 6 p.m. ET to announce his exit from the race.
The Republican was once considered a frontrunner for the GOP nomination, topping polls in Iowa and winning accolades from conservatives for his fights against labor unions during his tenure as governor of the state.
WATCH: Scott Walker responds to dismal poll numbers
But a series of missteps — and the rise of unconventional candidates like Donald Trump and Dr. Ben Carson — found him plummeting in national and key early state polls.








