From Pollster.com:

Public Policy Polling (D)

4/23-25/10; 387 likely Republican primary voters, 5% margin of error

Mode: Automated phone

Arizona

2010 Senate: Republican Primary

46% McCain, 35% Hayworth, 7% Deakin

Note that automated phone polling is not ideal.

Meanwhile, the Republic has posted a local poll from Behavior Research Center:

McCain leads Hayworth 54 percent to 28 percent with another 18 percent undecided.

In a potential general election battle against former Tucson Vice Mayor Rodney Glassman, the leading Democratic Senate candidate, McCain is ahead 46 percent to 24 percent with a significant 30 percent “uncommitted,” the poll says.

Hayworth also leads Glassman, who is not very well-known around the state yet, by 37 percent to 30 percent with 33 percent “uncommitted.”

This poll has a 5.7 percent margin of error; the two margins of error combined mean that both could still be quote-unquote correct.

Here’s Pollster.com’s current chart on the race: