A conservative research group in Michigan has issued a far-reaching public records request to the labor studies departments at three public universities in the state, seeking any e-mails involving the Wisconsin labor turmoil.

The group, the Mackinac Center for Public Policy, declined to explain why it was making the Freedom of Information Act request for material from professors at the University of Michigan, Michigan State and Wayne State University. But several professors who received the records request, which was first reported by Talking Points Memo on Tuesday, said it appeared to be an attempt to intimidate or embarrass professors who are sympathetic to organized labor.

This records request, which was filed Friday, comes several days after the Republican Party of Wisconsin made a records request to a prominent University of Wisconsin history professor, William Cronon, who had severely criticized the state’s Republican governor, Scott Walker, over his push for legislation to weaken public-sector unions.

The Mackinac Center, which describes itself as a nonpartisan research and educational institution and receives money from numerous conservative foundations, asked the three universities’ labor studies faculty members for any e-mails mentioning “Scott Walker,” “Madison,” “Wisconsin” or “Rachel Maddow,” the liberal talk show host on MSNBC.