Real estate investor Wil Cardon kicked off a four-day tour of Arizona on Tuesday in his quest for the Republican Senate nomination.

His stops on day one included Casa Grande, Tucson and Sun City.

Cardon is running to succeed retiring Sen. Jon Kyl (R). Rep. Jeff Flake is the favorite to win the Republican nomination, but Cardon has shown a willingness to put his own money into the contest, which could make things interesting. Cardon loaned his campaign $800,000 in the third quarter.

Earlier this week, Flake unveiled his campaign chairmen for each of Arizona’s 15 counties, a demonstration of his growing campaign infrastructure.