Florida Sen. Marco Rubio is headed to Arizona to headline a fundraiser for fellow Republican Sen. Jeff Flake.
Monday's luncheon event at a Scottsdale resort comes as Flake works to raise enough cash to fend off a primary challenge from former state Sen. Kelli Ward and other Republicans mull a challenge as well. If Flake makes it though the primary he's likely to face a strong 2018 general election challenge from Democratic U.S. Rep. Kyrsten Sinema.
Flake raised $1.1 million in the quarter that ended Sept. 30 and has $3.4 million on hand.
Arizona's junior senator angered President Donald Trump by criticizing him in a book Flake released this summer. Trump is working to recruit another GOP challenger because Ward is considered vulnerable to Sinema in a general election matchup.