Pledge would keep tens of millions of dark money out of Wisconsin.

MADISON - Senator Ron Johnson once again refused to give a yes or no answer to the Badger Pledge, a two page document offered by Russ Feingold that would eliminate dark money from Wisconsin's U.S. Senate election with Ron Johnson's signature.

On Monday, when reached by Politico for a response Senator Johnson responded "without giving a straight yes-or-no answer."

"Four days ago, we sent Ron Johnson a simple, two-page pledge that would keep millions in dark money ads out of Wisconsin’s Senate election. It shouldn't take this long to say yes or no to a bipartisan pledge that's proven to keep campaigns about the issues, not the attack ads. We still hold out hope Ron Johnson can make the right decision," said Russ for Wisconsin campaign manager Tom Russell.

Pressure is building on Senator Johnson as the conservative-leaning Beloit Daily News called for a campaign "...without the distortion of outside money..."

The Badger Pledge is the only tried and true proposal to keep third party groups from spending tens of millions of dollars on independent expenditure or issue advocacy advertisements. This spending accounted for over $40 million in Wisconsin's 2012 campaign cycle a startling number groups are poised to rival in 2016, without Johnson's signature on the Badger Pledge.

The pledge has drawn support from independent watchdog groups Public Citizen and Wisconsin Common Cause.