Business investor Wil Cardon said Friday he will challenge Rep. Jeff Flake for the Republican Senate nomination in Arizona.

Cardon will formally kick off his campaign this fall, but he is filing paperwork with the Federal Election Commission and collecting contributions on his new campaign website.

The philanthropist and first-time candidate is expected to make a down payment on the race that will top the $2 million Flake reported having in cash on hand at the end of June.

Cardon has signed up pollster Glen Bolger, media consultant Doug McAuliffe, who has worked for retiring Sen. Jon Kyl (R-Ariz.), and Phoenix-based communications consultant Jason Rose. He’s expected to announce more additions to his campaign team this week.

Cardon cites his stance on immigration, his work outside government and his support for transparent up-and-down votes in the Senate that could provide funding and jobs for Arizona as examples of differences between himself and Flake. The Congressman has been a leading opponent of earmarks, a position that Cardon agrees with.

“Right now you need to have people from the private sector who understand what it takes to create jobs and get the economy going,” Cardon told Roll Call in an interview. His company invests in businesses and real estate, and he considers himself a steward of the land.

The 40-year-old is married, a father of five, a fifth-generation Arizonan and a relative of Republican presidential candidate Mitt Romney. His father is a second cousin of Romney’s, and Cardon is best friends with Romney’s oldest son, Tag, with whom he attended Harvard Business School. He interned for Sen. John McCain (R-Ariz.) on Capitol Hill in 1992.