Public Policy Polling delivers new numbers about the race between President Barack Obama and Republican Mitt Romney in Arizona. The Democratic-leaning firm also looked at how the race changed with Jan Brewer, John McCain or Joe Arpaio as Romney's running mates, but concluded that those choices weren't all that plausible:

Arizona's looking a little bit less intriguing for Barack Obama than it did three months ago, when PPP polled it in the middle of the Republican primary contest. At the time it was tied but Mitt Romney's now opened back up a 50-43 advantage in the state.

Arizona makes a rare state where Romney actually has a positive favorability rating, at 46/45. Meanwhile Obama is unpopular there with only 41% of voters approving of his job performance to 56% who disapprove. Romney's ahead 48-38 with independents. Obama's dominating the Hispanic vote as he is most places, leading 63-35, but Obama's going to have to keep it closer with whites than his current 56-36 deficit if he's going to have a chance at carrying the state.

One thing that could make the race more competitive in Arizona, perhaps more so than other states, is Gary Johnson's presence on the ballot as the Libertarian candidate. He pulls 9% in Arizona and he takes a lot more support away from Romney than he does Obama, narrowing Romney's lead in the state to 45-41. History suggests it's quite unlikely Johnson would really pull 9% in the end but it shows how many voters are unhappy with their main choices in this race.

None of Arizona's major Republican politicians seem like terribly plausible Romney running mate choices, and none of them would help him in the state anyway. Voters continue to be closely divided in their feelings about Jan Brewer with 47% approving and 45% disapproving of her. If she was on the ticket Romney's lead over Obama actually drops to just 48-44. John McCain's 36/54 approval spread makes him the least popular Senator in the country in our current polling and if he was Romney's choice the race would tighten to 48-43 in the state. Joe Arpaio has a 46/45 favorability rating (down a net 6 points from 49/42 a year ago at this time) and with him as the running mate Romney would lead Obama only 46-44.

Arizona's still within the realm of possibility for Obama but he's going to have to really step it up with white voters to make it more competitive.