PHOENIX – U.S. Sen. Martha McSally of Arizona may have to worry about more than a strong challenge from Democrat Mark Kelly as she seeks to retain her seat next year.

Valley businessman Daniel McCarthy said Wednesday he would launch a “listening tour” around the state as he considers taking on the incumbent in the Republican primary.

His decision is being closely watched by Republicans in Arizona and in Washington, who worry a heated GOP primary could damage McSally in the 2020 general election.

McSally was appointed to John McCain’s Senate seat after losing to Democrat Kyrsten Sinema in last year’s race to replace retiring Republican Sen. Jeff Flake.

Jon Kyl held McCain’s seat for several months after McCain’s death before stepping down in December, when Gov. Doug Ducey appointed McSally.

McCarthy founded the Makeup Eraser cosmetics firm and Delex Realty with his wife.

Former U.S. Rep. J.D. Hayworth of Arizona told KTAR News 92.3 FM’s Arizona’s Morning News on Thursday that McCarthy’s background could help him.

“If we flip over all the cards, this guy’s a businessman. It’s very important in a campaign if you can self-finance, and if he can do that to get started, it will help his chances.”

McCarthy said in a phone call with supporters that he’s a more electable Republican than McSally.

When word spread in June that McCarthy was considering a run, McSally reached out to the party’s top national members for support, according to Politico.

The website said McSally “directly expressed concern” to President Donald Trump, Senate Majority Leader Mitch McConnell and National Republican Senatorial Committee Chairman Todd Young.

Soon after, Trump tweeted out an endorsement for McSally.

Politico also reported that Republican National Committee Chairwoman Ronna McDaniel asked McCarthy to stay out of the race.

McCarthy said Wednesday he won’t be intimidated by Republicans discouraging him from running.

The Associated Press contributed to this report.

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