The effort has outraged unions and higher education groups, leaving them fearful that other lawmakers will follow suit to unravel labor protections in higher education that have long been considered sacred ground.

Walker downplayed the changes at Sunday’s signing at a valve manufacturing facility in Waukesha, Wisconsin, emphasizing instead that tuition was being frozen in the University of Wisconsin system for two more years at the rate it was two years ago.

“We made college more affordable for college students and working families all across the state,” Walker said.

Walker signed the budget as he prepared to announce his run for the Republican presidential nomination Monday. The tenure fight could further endear him to conservatives skeptical of what some perceive as the ivory tower of higher education, and it serves to remind voters of his earlier effort to scale back collective-bargaining rights of public employee unions — including K-12 teachers — when he was first building a national profile.

The budget sent to Walker also includes other labor-related issues that frustrated unions, including a provision that rolls back a minimum pay protection for laborers working on local public construction projects like schools.

Cutting tenure protections is appealing to some college and university chiefs because it gives them more control over cutting programs when academic demands shift. Supporters of such protections say tenure is about protecting academic freedom and attracting high-quality faculty.

Walker has said the changes to tenure are needed to give the state university system more flexibility and financial leverage.

Specifically, the changes allow the University of Wisconsin system Board of Regents — 16 of whose 18 members are appointed by the governor — to set tenure policies instead of having tenure protections spelled out in state law.

He said the change in Wisconsin “modernizes the concept of tenure by authorizing the Board of Regents to enact such policies.”

Walker, who didn’t graduate from college, introduced the tenure issue in an initial budget proposal that included $300 million in cuts over two years and significantly restructured the state’s public higher education system.

A GOP-led legislative committee approved the tenure change, then went a step further and approved a measure that modifies state law to specify that regents can fire faculty when they deem it necessary because a program has been discontinued or changed in other ways, not just when a financial emergency exists, as it had been spelled out in state law.

The committee didn’t give Walker all he wanted, however, and it reduced the cuts from $300 million to $250 million — cuts that Walker signed into law.

Rebecca M. Blank, chancellor of the University of Wisconsin-Madison, made a last-ditch plea late last week for Walker to veto the tenure changes.

“The inclusion of the current language allowing termination or layoff of faculty for certain budget program decisions … has created negative national publicity that will hinder the ability of UW-Madison to attract and retain world-class faculty, many of whom bring substantial federal and private-sector investment into the state of Wisconsin,” Blank said in a letter to Walker.

Already, the Board of Regents has passed a resolution to adopt the tenure language as it stood in state law before the change. A tenure task force is reviewing the policy, including the handling of layoffs.

Wisconsin’s system is rare in that tenure protections had been written into state law. Tenure policy is typically determined by an institution or a state board.

Nationally, about 51 percent of public institutions had a tenure system in the 2013 school year. That’s down from 59 percent a decade earlier, according to federal data.

Walker has said while discussing his proposal that “maybe it’s time for faculty and staff to start thinking about teaching more classes and doing more work.” And Walker has defended his plan by noting he has a child enrolled in the University of Wisconsin, so he has a vested interest in ensuring his plan works well.