With a new report from Cochise County, Congressman Ron Barber lost a bit of the margin he picked up in Pima County earlier today, but he still leads GOP challenger Martha McSally by 512 votes.

But for a second night in a row, McSally did not retake the lead after Cochise County reported its count.

From what we understand, there are still about 2,000 early ballots left to count in Cochise County, which was McSally's stronghold. There are also somewhere around 2,000 provisional ballots, but it's unclear how many of those will end up being counted.

Meanwhile, Pima County still has roughly 4,000 early ballots (which have trended toward Barber) and about 27,000 provisional ballots. Those provisionals are the real X-factor in this race, since there's no good model as to how provisional voters behave (especially in a case where some of those provisional ballots were the result of a computer glitch that left names off their regular spots on the voter rolls at polling places). If they behave like early voters, it will be good for Barber; if they behave like day-of-election voters, it will be good for McSally.

You'll find more on the CD2 results here.