File Photo: Republican leader and 2-time Governor of Wisconsin Scott Walker. (Agence France-Presse)
The man once considered a rising star of the Republican Party is expected to announce Monday that he is pulling out of the race for the White House.
Wisconsin Governor Scott Walker is just the latest victim of Donald Trump's surprise surge in the race to win the Republican nomination for 2016.
The New York Times said that Walker is due to confirm his withdrawal at a 2200 GMT press conference in Madison, capital of Wisconsin, the state he has governed since 2011.
"People don't stop running for President because they run out of ideas (...) they stop running because they run out of money," Terry Sullivan, campaign manager for rival Marco Rubio, said at a National Review event.
Of the 17 initial Republican candidates, 15 remain after Rick Perry, former governor of Texas, dropped out on September 11.
The 47-year-old Walker started the year with a bang and was even leading in some polls in the spring.
But his star has been on the wane since, coinciding with the emergence of Trump as a genuine contender for the Republican ticket.
Walker's approval rating has plummeted, falling to nearly zero in a CNN poll published Sunday.