The U.S. Senate race in Arizona between Republican incumbent John McCain and Democrat Ann Kirkpatrick has reached a new milestone: For the first time since Kirkpatrick announced she was challenging McCain, polls show the two candidates tied at 48 percent.

For months, Kirkpatrick has been slowly catching up to McCain, but data released today from the latest Rocky Mountain Poll shows she’s actually devouring – if not overtaking — his lead among important demographic groups like rural voters, Republicans, and women.

In general, residents of rural counties in Arizona tend to vote Republican, but as of this week, McCain has lost his lead there, meaning that for the first time this election season, more rural voters say they plan to support Kirkpatrick than McCain — 43 percent to 39 percent.

Experts with the Behavior Research Center, which conducts the Rocky Mountain Poll, call this “a modest but important pattern” that appears to have started in January.

Another important trend pollsters picked up on is McCain’s growing unpopularity with his own party — while 59 percent of registered Republicans said they supported McCain in January, that number has since dropped to 51 percent.

Kirkpatrick, meanwhile, appears to be capitalizing on his unpopularity, and currently has the support of 27 percent of GOP voters.

No one can say for sure why those in McCain’s base are defecting, but a statement from the Behavior Research Center suggests: “The deeply partisan and bitter GOP presidential primary elections, plus McCain playing a low-key role, may be having an impact on voting patterns in Arizona.”

In fact, this most recent poll found that overall, “Republicans are the most undecided about how to vote in this Senate race — 22%, compared to 16% among Democrats and only 12% among Independents.” (It's important to note that pollsters didn’t ask about McCain’s two Republican primary competitors, state Senator Kelli Ward and businessman Alex Meluskey, though both are widely considered long shots.) Democrats, on the other hand, are flocking to Kirkpatrick – she’s up 10 percentage points since January – and Independents appear to be about equally divided.

Kirkpatrick also has a commanding lead among female voters (47 to 37 percent), but men still prefer McCain (49 to 34 percent), pollsters say.

#AZ women only make 84% of what men earn -- but McCain won't fight to close the gap https://t.co/jpJZKCVmNT #AZSen #EqualPayDay — Ann Kirkpatrick (@Ann_Kirkpatrick) April 12, 2016

The results are also mixed when the data is broken down by age: McCain has a sizable lead among 35- to 55-year-olds, Kirkpatrick has a sizable lead with voters 55 and older, but the two are nearly tied with voters under 35.

Interestingly, “Hispanic voters may yet turn out to be an island of strength for John McCain as he is currently garnering 50 percent of their vote compared to only 32 percent in January,” notes a statement from the Behavior Research Center.

Kirkpatrick’s support among Hispanics has dropped from 39 percent in January to 37 percent today, but she’s killing it when it comes to non-Hispanic minorities: 66 percent to McCain’s 19 percent.

With six-plus months left until the November general election, anything could happen, but as the Washington Post noted earlier this month, this race is gearing up to be one of the most competitive U.S. Senate races in the country.

**Update 4/16/16: Lorna Romero, spokeswoman for John McCain, had this to say about the Rocky Mountain Poll results:

"We are confident that when voters tune into the race and compare John McCain’s record of fighting for Arizonans to Democrat Congresswoman Ann Kirkpatrick’s clear record as a rubber stamp for Obama's liberal agenda, they will proudly vote McCain. Regardless of polling, John McCain has always taken every election seriously and will continue to campaign hard for each vote.”

