Timothy Jost, a law professor at Washington and Lee University and a prominent Affordable Care Act supporter, agreed.
"This attempt to bully these programs is shameful," he said.
The administration recently awarded $67 million in grants to 105 navigators — mostly healthcare organizations and community groups, which will use the money to help explain the healthcare law and guide consumers through parts of the enrollment process.
The Energy and Commerce Committee did not release the letter, which was signed by its Republican leaders. A committee spokeswoman did not immediately respond to an inquiry about how many organizations received the letter.
In their letter to grant recipients, House Republicans sought detailed information about how the organizations would use their grant money and the grant process.
Republicans asked the grant recipients to provide "all documentation and communications related to your Navigator grant," including all communications between the applicants and any federal agency.
Republicans also specifically asked for any communications with Enroll America, the nonprofit group with close ties to the White House that is helping to promote enrollment in the law's new insurance plans, including "discussions or documents related to geographic area."
The states that received the largest sums of navigator grants are the same states Enroll America is targeting for its outreach effort. Those states, including Texas, Florida and Ohio, have high numbers of uninsured people, as well as Republican governors unwilling to make the case for enrollment.
Republican lawmakers have long feared that the navigator program would be a magnet for fraud and identity theft. In their letter to grant recipients Thursday, lawmakers asked for detailed information about how the organizations would train their workers and how they might use the information they collect.
The lawmakers specifically asked whether organizations "may contact individuals who have utilized your services as a Navigator for the purposes of fundraising, voter registration efforts, campaign activities, or any other reason."
The administration has defended the navigators program as a neutral and necessary form of in-person assistance to help consumers make sense of the widely misunderstood healthcare law.
Navigators will receive roughly 20 hours of training from the Health and Human Services Department, and are not generally tasked with collecting personal healthcare information.
Navigators will help consumers understand and compare their options, the administration has said, but they will not submit consumers' applications and cannot be paid by a particular insurance company.
— This post was updated at 4:04 p.m.