“This is a good issue for Republicans,” Mackowiak added. “We want to maximize it.”

The Republican-controlled House Energy and Commerce Committee has launched an investigation into the fundraising to determine whether it involved regulated companies and has asked nearly a dozen healthcare firms including major insurers such as Aetna Inc, a member of Enroll America’s advisory council, to say whether they have received solicitations.

Republicans in the House and Senate have also called on the non-partisan Government Accountability Office to investigate.

“People are watching it very closely. We’re hearing about it from constituents, people who are incredibly concerned,” said Republican Representative Marsha Blackburn.

Enroll America was launched in September 2011 in part by leaders of Families USA, a key backer of the healthcare reform effort as it moved through Congress in 2009 and 2010. It is led by Anne Filipic, who worked on public engagement projects in the Obama White House. It’s managing director, Chris Wyant, directed Obama’s eastern Ohio field operation during the 2012 election campaign.