The U.S. Senate race in Arizona to replace retiring Republican Jon Kyl was supposed to be an easy hold for the GOP. But the last several polls have shown the race is tightening between the Republican candidate, Congressman Jeff Flake, and his Democratic opponent, Richard Carmona, a former U.S. surgeon general under George W. Bush. One poll from last week even showed Carmona two points ahead of Flake, which was surprising since Flake led Carmona by double digits as recently as June. The Real Clear Politics average shows Flake with just a 2.3-point lead.

That environment explains the latest ad from the Flake campaign, which features Dr. Cristina V. Beato, the acting assistant secretary of health during Carmona’s tenure as surgeon general. Beato alleges that Carmona “pounded” angrily on her door in the middle of the night while she and her family slept. Watch the ad below: