A new law in Indiana requires professors in public universities to foster a culture of “intellectual diversity” or face disciplinary actions, including termination for even those with tenure, the latest in an effort by Republicans to assert more control over what is taught in classrooms.

The law connects the job status of faculty members, regardless of whether they are tenured, to whether, in the eyes of a university’s board of trustees, they promote “free inquiry” and “free expression.” State Senator Spencer Deery, who sponsored the bill, made clear in a statement that this would entail the inclusion of more conservative viewpoints on campus.

The backlash to the legislation, which Gov. Eric Holcomb, a Republican, signed March 13, has been substantial. Hundreds wrote letters or testified at hearings, and faculty senates at multiple institutions had urged the legislature to reject the bill, condemning it as government overreach and a blow to academic free speech.

“The whole point of tenure is to protect academic freedom,” said Irene Mulvey, the president of the American Association of University Professors, who described the law as “thought policing.”

Colleges nationwide have been buffeted by debates about academic freedom in recent years. Several states, including Florida, Texas and Nebraska, have proposed bills limiting tenure, some of which have passed. More broadly, Republican-led states have targeted diversity programs in universities; those bills, which have restricted or eliminated those programs, have had more success becoming law, with such measures in place in at least a half-dozen states.

Under the Indiana law, which goes into effect in July, university trustees may not grant tenure or a promotion to faculty members who are deemed “unlikely” to promote “intellectual diversity” or to expose students to works from a range of political views. Trustees also may withhold tenure or promotion from those who are found “likely” to bring unrelated political views into the courses they are teaching.

Faculty members who already have tenure would be subject to regular reviews to determine if they are meeting all of these criteria, and if the board concludes they are not, they could be demoted or fired. The law also requires colleges to set up a procedure for students or other employees to file complaints about faculty members considered to be falling short on these requirements.

Boards are not, under the law, allowed to penalize faculty for criticizing the institution or engaging in political activity outside of their teaching duties. The restrictions do not apply to private university faculty members.

“I have faith in our public universities to faithfully implement this law to foster the successful growth and intellectual vibrancy of academia while protecting the rights of all individuals,” Governor Holcomb said in a statement.

In describing the rationale for the legislation, Mr. Deery, a Republican, pointed to surveys that showed a significant decrease in the number of Republicans who have confidence in higher education, a decline many on the right attribute to faculty bringing political views into the classroom. He also brought up the controversies that have erupted in recent months about antisemitism on campuses, leading to the resignation of university presidents and demands of greater oversight by university trustees.

“Recent events and blatant antisemitism have placed a spotlight on the hyper-politicalization and monolithic thinking of American higher education institutions, and many are warning that universities have lost their way,” Mr. Deery said after the bill passed in the Senate. The legislation, he said, “prods the leaders of these institutions to correct the course.”

Alice Pawley, a professor of engineering education at Purdue University, said that many faculty members in Indiana were angered by the new restrictions, and that “nobody trusts that this is actually going to be fairly applied.” Many felt discouraged about their job security, believing it would be at the mercy of trustees who are not experts in their fields and would be making decisions on the basis of highly subjective criteria, Dr. Pawley said.

“This policy is a clever way of looking reasonable but producing a climate where people are always looking over their shoulder to see who’s going to judge them,” she said.

Even some who are troubled by the lack of conservative voices on campuses were skeptical. Keith E. Whittington, a politics professor at Princeton University, expressed concern around the vagueness of the law, including the uncertainty around what will be needed to meet the requirements.

What distinguishes Indiana’s law from other similar measures, according to Dr. Whittington, is that it “doesn’t try to punish people for introducing controversial ideas in their classes.” Rather, it “tries to punish people for not introducing enough ideas into their classes. And that’s still an intervention in people’s own professional judgment about what they ought to be teaching.”

In practice, Dr. Whittington said there will be a lot of professors “running scared and trying to figure out not only, ‘How do I construct a class that I think is intellectually coherent and satisfying and educationally useful?’” but also “‘How do I shelter myself from potentially getting fired?’”