Begich, Landrieu and Pryor all lead their likely opponents by three points or a less, a sign all three will have tough races this fall.
If Begich faces either Alaska Lieutenant Gov. Mead Treadwell (R) or former Alaska Natural Resources Commissioner Dan Sullivan (R) he's in a tight race. But if 2010 Senate nominee Joe Miller (R) wins the primary, a less likely scenario, Begich's lead jumps to a 27-point edge.
The surveys were conducted by the GOP firm Harper Polling in the last
week of September, before the government shutdown that has hurt
Republicans' numbers nationwide.
A Crossroads spokesman says the group did not poll other top-tier Senate races like Montana and North Carolina. The polling included a primary test showing Capito with a clear lead over her opponents, but the spokesman says they didn't conducted similar surveys on Alaska's GOP primary or test a Tea Party candidate in Louisiana.
This post was updated at 10:40 a.m.