There is not much for labor leaders to like in the Republican Party's 2016 platform. It is one of the toughest the party has had in the last four decades in terms of calling for union power to be reined in, a direct response to President Obama, one of the most pro-union presidents in decades.

The latest platform calls for such reforms as a national right-to-work law to prohibit workers from being forced to join or support a union. It also demands that the National Labor Relations Board, the main federal labor law enforcement agency, be defanged; opposes the Labor Department's recent move to expand worker overtime requirements; and calls for the repeal of laws that benefit unions in federal contracting.

The new version promises to "bring labor law into the 21st century" by getting rid of regulations that it says strangle innovation, shackle employers and employees alike and have no place in the modern economy. "Republicans believe that the employer-employee relationship of the future will be built upon employee empowerment and workplace flexibility," it states.

The platform even questions whether unions should be allowed in the public sector at all.

"The unionization of the federal workforce, first permitted by Democrat presidents in the 1960s, should be reviewed by the appropriate congressional committees to examine its effects on the cost, quality and performance of the civil service," it declares.

The platform met with a thumbs down from labor leaders. "Oh, where to begin," said Ed Wytkind, president of the AFL-CIO labor federation's Transportation Trades Department. "Throughout the platform there are endless attacks on the rights of workers to freely join a union and bargaining collectively for better wages, working conditions and retirement security."

J. David Cox, Sr., president of the American Federation of Government Employees slammed its opposition to public sector unionism. "The Republican platform also shows a horrible irresponsibility for the public interest in its embrace of privatization. Handing over the government's work to profit-hungry contractors at the expense of public safety and health is a guarantee of scandal," he said.

He particularly scorned the call for a national right-to-work law, saying it would "gut strong unions." The laws prohibit labor-management contracts that force all employees to join a union or pay it a fee as a condition of employment. More than half of the states have the laws, which are associated with unions losing dues revenue caused by members taking advantage of the option to drop their membership.

As tough as it is, little of the platform appears to be Republican presidential candidate Donald Trump's doing. The 2016 platform is marginally more favorable to unions than the 2012 version, drafted when former Massachusetts Gov. Mitt Romney was the party's presidential nominee.

The 2012 one, for example, was silent on the issue of the minimum wage, while the current one says that is "an issue that should be handled at the state and local level," indicating that the party won't oppose increases at those levels — even to the $15 rate liberals are demanding.

The previous GOP platform also explicitly opposed "card check," unions' attempt to boost their chances in workplace organizing by getting Congress to eliminate federally monitored secret ballot elections for unions. The current platform doesn't mention card check, though that may simply be a reflection of the issue dropping off the radar after Congress refused to take it up.

The 2012 and 2016 GOP platforms are otherwise largely the same regarding labor. That represents a considerable shift from the party's stance just a decade ago, an analysis of the GOP platforms' language by the Washington Examiner found. While the Republicans have always been closer to big business than big labor, curbing union power became a serious issue for them only after President Obama's election in 2008.

"It is a positive development that the GOP recognizes the serious harm [Obama's] federal labor agencies have inflicted on job creators and workers. In a time of economic recovery, we must remove roadblocks to economic growth — not build them higher with burdensome and costly regulations," saids Trey Kovacs, labor policy expert for the free-market Competitive Enterprise Institute.

The one consistent thread through all GOP platforms over the last four decades has been support for the right of states to enact right-to-work laws. That was merely an endorsement of the status quo, though. States have had that right since Congress passed the Taft-Hartley Act in 1947. Prior to Obama's presidency, they had little else to say on the issue.

The 1996 platform, drafted in the year that President Bill Clinton was the incumbent and Senate Republican Leader Bob Dole was the GOP candidate, devotes slightly more than a 100 words to the topic. In addition to right-to-work, it calls for vigorously enforcing the Hobbs Act, which prohibits unions from engaging in extortion or violence, and the Supreme Court's Beck decision, which said that union members can demand that that their dues not be spent on political activity. The 1996 platform did, however, affirm workers' rights to collective bargaining and did not call for any significant reform of existing law. GOP platforms going back to 1976 took most the same position.

The 2004 version, drafted when then-President George W. Bush was running for re-election, was the most relatively pro-union in recent decades. That one called for expanding the number of workers covered by overtime protections.

"We are proud of the fact that 1.3 million additional workers now have guaranteed overtime protections as a result of Republican efforts to modernize labor laws left untouched since 1949," it declared. The 2008 version was largely the same.

A big shift happened in 2012, the first time a platform was drafted after Obama took office. He has been arguably the most pro-union president since Harry Truman, having pushed the Labor Department to act more aggressively in favor of unions and having appointed a pro-union majority to the National Labor Relations Board.

That in turn has prompted the GOP to look more closely at curbing union power. The 2012 platform, for the first time in decades, did not endorse the right to collective bargaining, being silent on the issue. For the first time, it called for a national version of a right-to-work law, advocated repealing laws that aid unions in federal contracting, raised the question of whether unions should be barred at the federal level and accused the president of "encouraging illegal actions by regulatory agencies from the NLRB to the EPA."

The 2016 version devotes more than a thousand words to labor issues, 10 times what the 1996 version did. It accuses the administration of pandering to unions and harming the economy.

"Instead of facilitating change, the current administration and its agents at the National Labor Relations Board are determined to reverse it. They are attacking the franchise model of business development, which is essential to the flexibility and creativity of the new economy. They are wielding provisions of the Fair Labor Standards Act from the 1930s, designed to fit a manufacturing workplace, to deny flexibility to both employers and employees," it states.