In the eight months since the New York attorney general, Eric T. Schneiderman, announced the first investigation of Exxon Mobil over its past research statements about climate change, nearly 20 other state attorneys general have voiced their support.

But Exxon Mobil has increasingly been pushing back, fighting subpoenas in court and winning the support of lawmakers and friendly state attorneys general who have attacked the investigations as flashy political prosecutions dressed up as legal inquiries.

The company, for example, filed a motion on Wednesday in federal court in Texas to block a demand for documents by the Massachusetts attorney general, Maura Healey, calling it a “fishing expedition.”

The filing argued that Ms. Healey was “abusing the power of government” to silence the company, and that she made statements in a March news conference with Mr. Schneiderman and other state law enforcement officials that suggested she had already made up her mind about what her investigation would find.