All Dole has to do is come back with something like this:

“Is it more important that some policy wonk rates me 93rd in effectiveness, or that the American people give the Democrat-led Congress a NINE percent approval rating? The Democrats sabotage the effectiveness of myself and other Republican senators by refusing to even vote on the issues most important to Americans. Issues like energy independence, growing the economy with high-paying jobs, and securing our borders. That ad doesn’t mention those issues, because it’s the Democrats who are truly ‘ineffective’”.