The super PAC aligned with Speaker Paul Ryan, R-Wis., warned Tuesday that the Democratic Party’s resource advantage might be too much to handle for the Republicans’ vulnerable House majority.

The Congressional Leadership Fund has raised more than $160 million and invested that money in television, radio, and digital advertising as well as a homegrown voter turnout operation to assist targeted Republican incumbents who might not benefit from the work on the ground being done by the national party. But it might all be for naught, CLF executive director Corry Bliss warned in a memorandum issued to the group’s donors one week before Election Day.