Founded in the late 1990s, RMSP raises money to support the Republican Party’s moderate wing. GOP lawmakers embraced the RMSP name when, in 2017, it launched the caucus — an official member organization registered in the U.S. House. The member caucus was driven by a desire to counterbalance the weight of the conservative wing inside the House GOP. Lawmakers believe that rebuilding the centrist coalition is key to improving the GOP’s odds of winning a House majority in 2020.

That November, lawmakers were licking their wounds. Main Street Caucus Republicans had been hit hardest in the election — 18 House incumbents defeated — and they wanted to question Chamberlain about her organization’s political decision-making in 2018. At issue was $722,000 still resting in Defending Main Street, the outfit’s superPAC — one of at least five political or advocacy organizations under the RMSP umbrella run by Chamberlain — and why those resources hadn’t been deployed to any number of competitive races where they could have made a difference.

Chamberlain defended her work, pointing to the Republicans who survived 2018 with the help of significant resources — nearly $6 million — from the RMSP network. RMSP told NPR that $722,000 wasn’t spent because those funds had been earmarked for 2020.

That Nov. 28 meeting set off a cascading series of events over the next two months. Lawmakers demanded, and were denied, an audit of RMSP’s activities. Lawmakers ultimately abandoned the member caucus, and others quietly distanced themselves from RMSP and Chamberlain.