For over 100 years, the American public viewed labor unions in a positive light. But after unions were body-slammed in battles against three not-so-free trade agreements negotiated by Democrat Presidents, manufacturing jobs plummeted and public opinion of unions went negative for the first time during Obama Administration.

Distrusted as more interested in the leftists’ political agenda than working Americans, unions joined conservative Republicans to block the Trans-Pacific-Partnership last week. This new coalition in support of American jobs represents a tipping-point political event.

Polls show that despite unions providing the foot-soldiers and cash to get many Democrats elected, over 60 percent of Democrats support job killing trade deals, compared to about 50 percent of Republicans. This explains why each of the last four job killing trade deals was negotiated by a Democrat President:

North American Free Trade Agreement negotiated by Clinton in 1994 promised a net gain of 200,000 American jobs, but is estimated to have cost 692,900 jobs;

Permanent Normal Trade Relations (aka most favored nation) for China negotiated by Clinton in 1999 was supposed to support 150,000 American jobs, but appears to have directly cost 3.2 million jobs and contributed to the loss of 6 million U.S. manufacturing jobs over the next six years;

U.S.-Korea Free Trade Agreement negotiated by Obama in 2012 was supposed to add 70,000 jobs, but so far has lost 60,000 American;

Trans-Pacific Partnership negotiated by Obama claims to “boost U.S. economic growth, support American jobs, and grow Made-in-America exports.” But the top proponents of the treaty are Hollywood moguls, multi-national corporations that off-shore jobs, and tech companies that want expanded HB-1 visas to import millions of cheap engineers from Asia to replace Americans.

Ever since President Franklin Roosevelt’s re-election campaign in 1936, labor unions and the Democratic Party have worked together in U.S. politics. Unions were supposed to provide votes, money, and volunteer time, and Democrat officeholders were supposed to offer center-left policy benefits that help workers when they took office.

Since 1994, when unions represented 17.5 percent of all U.S. workers, the unions have continued to perform their share of the partnership. But the “policy benefits” offered by the Democrat Party have often been against the economic well-being of union members. As a result, the percentage of workers represented by unions fell to 12.4 percent.

The entire decline in union representation fell on private sector unions. Public sector unions continued to grow, and a majority of all union members (51 percent) work in government. More than twice as many union members now work in the U.S. Postal Service as in the domestic auto industry. This represents a historical reversal, given that President Roosevelt opposed labor unions representing government employees.

The most defining partisan issue between Republicans and Democrats through the 1980s was support for unions. But according to the latest Pew poll, support for social safety-net and environment are now the two top partisan issues that define Democrats. The percentage of Democrats that consider themselves liberal has also jumped from 28 percent under Clinton to 38 percent during the President Obama era.

Clinton and Obama campaigned promising to oppose trade agreements that might threaten American jobs. Once in office, both Democrat administrations pushed “free-trade” treaties that eviscerated blue-collar union employment.

Former Federal Reserve Vice Chairman Alan Blinder and former Chairman of President Obama’s Council of Economic Advisers Alan Krueger warn that one in every four American jobs are still vulnerable to being off-shored in the foreseeable future, with the most vulnerable being those holding college and professional degrees that earn over $75,000.

What is left of union membership understands that, over the last 20 years, they may have been responsible for their own economic demise by supporting Democrats who pushed through not-so-free trade legislation. The labor union and conservative Republican revolt against Trans-Pacific Partnership could serve as the foundation for a coalition whose defining partisan issue is supporting the interests of American workers.