Normally we reserve open threads for national or statewide elections, but if Jesse Kelly pulls the upset tonight on a wave of Republican enthusiasm there’s going to be a full-fledged panic attack among O and his inner circle. Reason enough to flag it, just in case. Kelly’s got an awfully heavy lift: He’s running to replace Gabby Giffords and is facing Ron Barber, a former Giffords aide who was also shot in Tucson last year. That’s a lot of sympathy for Kelly to have to overcome in a district that already sent Giffords to Congress three times. The most recent public poll shows a double-digit Barber lead, but ABC thinks things could get interesting tonight:

While a new (non-airworthy) poll out Monday showed Barber ahead of Kelly by 12 points, insiders on both sides say their polling shows the race much tighter. Many of those closest to the contest give Barber a narrow advantage.

A win by Barber would be more than just a victory for the extended “Giffords family,” it would be a psychological boost for a White House that has endured a rough couple of weeks. After all, this is not a slam dunk Democratic district. McCain won this district in 2008, Bush carried it in 2004, and Republicans have a significant registration advantage here as well.

A Kelly win would provide another example of a Republican enthusiasm advantage over Democrats – i.e. Wisconsin recall. Furthermore, it would undercut one the Democrats’ main arguments for the fall campaign: that GOP support of Social Security and Medicare reform (like the Ryan budget) is politically toxic. Outside groups supporting Barber have pummeled Kelly with his own words on these entitlement programs. As the Arizona Daily Star reported: “Barber and Democrats remind voters daily that two years ago Kelly said he wanted to privatize and phase out Social Security and eliminate Medicare. They slam his pledge this go-round to protect the programs as a disingenuous trick.”

National Journal notes that there was an unprecedented amount of early voting in this election and it seems to have been driven by higher-than-expected returns from Democratic voters, a bad sign for Kelly given that Giffords used an early voting advantage to beat him two years ago. Even worse news: The newly redrawn district apparently will lean a bit more Democratic in November, so Kelly’s best shot is to win tonight and then hope that his (brief) incumbency will give him an edge in the fall. Might be now or never.

The polls close at 10 p.m. ET. Results should be available at the Secretary of State’s website. Oh, and as for the other big race today, George Allen won the Virginia Republican primary easily. No surprise.