Are the big three Senate races slipping from Dems?

In Alaska, the conservative base has rallied behind Republican Dan Sullivan after a contentious August primary, and Democratic Sen. Mark Begich was stung by backlash over an attack ad he later decided to pull. In Louisiana, Democratic Sen. Mary Landrieu has been hammered over revelations that she improperly charged taxpayers for charter flights. And in Arkansas, Republican Rep. Tom Cotton — who’s been knocked as robotic on the stump, especially compared to his backslapping opponent, incumbent Sen. Mark Pryor — has improved noticeably in that department…

If Republicans manage to oust the trio of senators, they’ll have Obama to thank as much as their opponents.

A Suffolk University/USA Today poll of Arkansas last week pegged Obama’s approval at 34 percent. For context, this is a poll that put Pryor ahead by 2 points, within the margin of error. Eleven of the past 13 public polls in the Razorback State show Cotton in the lead, though often in the low single digits. A CNN/ORC poll released Sunday showed Obama’s approval rating at 37 percent among likely voters in Louisiana — and only 17 percent among whites. It’s much the same story in Alaska.

Obama was never popular in these places, and the drop in his numbers has actually been bigger in purple states like Iowa, Colorado and New Hampshire. But at a certain point, even the best-run campaign cannot overcome a White House so disliked by voters.