The 50 million Justice Department records may include unredacted voter lists voluntarily handed over by more than a dozen Republican-led states in the months prior.

The 166 pages of records, released on Wednesday by the advocacy group Democracy Forward, offer a detailed look inside one arm of the Trump administration’s escalating election-integrity campaign, which has marshaled federal investigators, immigration databases and voter records in an effort to identify noncitizens suspected of illegally registering or voting. They show the extensive infrastructure the administration has built within its immigration enforcement agency to pursue probes aligned with Trump’s election fraud beliefs, with multiple layers of data reviews, dozens of organizations investigated, primary elections tracked and weekly reports summarizing the progress of the various projects.