Arizona Congresswoman Martha McSally is launching her bid for the U.S. Senate on Friday. She becomes the third high-profile Republican to enter the race to replace retiring GOP Sen. Jeff Flake in a state deeply divided by President Donald Trump's agenda.
The Arizona election will showcase the explosive feud between the Republican Party's establishment and its hardline anti-immigration wing -- all in a border state that features the nation's fourth largest Hispanic population.
McSally, a retired Air Force colonel and the first female fighter pilot to fly a combat mission, will fly herself across Arizona Friday in a World War II fighter plane to personally announce her candidacy. Former Sheriff Joe Arpaio, an immigration hardliner, and former state Sen. Kelli Ward, a vocal Trump advocate, are also GOP candidates.