Eight years ago, the Koch brothers' network spent millions to help boost the Tea Party wave.
In 2010, the right benefited from historical trends: Midterm elections are traditionally disastrous for the president's party. Close to a decade later, the wave is rolling back in.
"You're just going against the tide. You're going against history, which makes it a little tough," quipped network official Tim Phillips, president of the grassroots organization Americans For Prosperity.