Though most election forecasts have been giving the GOP a better than even chance of winning control of the Senate in November, Begich and Pryor have for months been praised for running strong races amid particularly challenging circumstances.

In the latest RealClearPolitics average of polls, Begich leads Sullivan by 4.6 percentage points in deep-red Alaska, and Pryor trails Cotton by just 1.7 percentage points in Arkansas — a state that President Obama lost to Mitt Romney by a 24-point margin in 2012.

RealClearPolitics senior elections analyst Sean Trende warned against reading too much into the Democrats’ recent gambit — for the time being, at least.

“When you see these sorts or over-the-top ads being run, it is frequently a sign of panic,” Trende said. “With that said, I don’t know that we have enough evidence here to draw firm conclusions. I think Pryor might well be employing a ‘kitchen sink’ approach, but Begich and Burke seem to be doing relatively well in the polls. In those cases, it might just be a boneheaded move by Begich’s team, and a stupid comment by [Wasserman Schultz].”