PHOENIX - With less than nine months to go until the 2022 primary, Arizona Attorney General Mark Brnovich is holding firm as the clear Republican front-runner for U.S. senate, according to polling released Tuesday.

Brnovich is the top choice among 27% of the registered GOP voters surveyed by Phoenix-based research firm OH Predictive Insights earlier this month.

Former Arizona National Guard leader Mick McGuire is the only other hopeful in double figures at 12%.

A pair of businessmen, Blake Masters at 9% and Jim Lamon at 5%, and Arizona Corporation Commissioner Justin Olson at 2% round out the polling.

The findings reported were based on an opt-in panel survey conducted Nov. 1-8, with a margin of error of 3.7%.

Brnovich's numbers haven't changed since September polling by OH Predictive Insights, but McGuire fell 2 percentage points further behind.

Each of the other candidates picked up 2-3 points. Olson wasn’t included in the September polling because he hadn’t yet entered the race.

The "unsure" column declined from 51% to 46% in the last two months.

Whoever gets the GOP nomination will be positioned to make a strong challenge against the Democratic incumbent, Sen. Mark Kelly, in a race considered a key to control of the chamber.

Polling of the registered voters from both parties showed Kelly at 40% and any Republican candidate at 39%, with 21% unsure.

The 2022 primary election will be held Aug. 2. The general election follows on Nov. 8.