Steward Health Care CEO Ralph de la Torre fired back Thursday at lawmakers trying to force him to testify about the downfall of the hospital chain he runs. Hours after the U.S. Senate on Wednesday unanimously asked DOJ to prosecute de la Torre for criminal contempt of Congress — the first such referral since 1971 — the executive issued a statement saying he would "not be intimidated" by the move. De la Torre was disappointed the Senate decided "to continue their violations of Dr. de la Torre's constitutional rights, particularly those protected under the 5th Amendment of the U.S. Constitution," a spokesperson told the Globe in an early morning email after the vote. "The U.S. Constitution stands above the government to protect all Americans from precisely the kind of assault on our rights that we are witnessing here."