She likened the situation to learning that Sen. Kent Conrad, the last remaining Democrat in North Dakota's congressional delegation, would retire in 2012.
Initially, it looked like Democrats would have next to no chance to be competitive in the race for Conrad's replacement. But the entrance of former state Attorney General Heidi Heitkamp (D) has turned the race into a toss-up, and Democrats are now bullish about holding on to that seat.
"Ben Nelson was being attacked viciously," she said, referring to attack ads aired by outside conservative group Crossroads GPS targeting Nelson. "We're not going to sit back and watch one of our senators just be inundated and not support them."