Left-leaning advocacy groups have found a backdoor way to kill banking access for millions of Americans: burying federal regulators in coordinated, astroturfed comment campaigns.

A collection of progressive nonprofit groups appears to have found a formula beyond traditional lobbying to achieve their policy goals: hijacking federal regulatory comment periods. In an effort to block approvals they view as nefarious, these groups have launched coordinated campaigns that astroturf comments to regulators and build a talking-points echo chamber designed to grind approvals for novel banking providers, known as “fintechs,” to a halt. The financial consequences for hundreds of thousands of Americans could be dire.