House Majority Leader Eric Cantor spent almost a million dollars in his unsuccessful effort to stop David Brat's primary challenge. Brat campaigned as an orthodox conservative, but that didn't stop Cantor from portraying him as a "liberal college professor" with ties to Democratic Governor Tim Kaine.
These ads were too much for FactCheck.org, which said that Cantor "misrepresents his primary opponent’s role on a state economic forecasting board." It notes that the board Brat served on focused on technical economic issues. Brat never advised Kaine on tax policy, as Cantor's ads imply.