The Democratic Party’s increasing dependence on public employee unions is a serious disadvantage in the political battles of today and the years to come.

Labor has always been the backbone of the Democratic coalition, but the collapse of America’s industrial unions and the aggressive organization of well-paid government workers has caused a seismic shift in the party’s composition. The party of steelworkers and coal miners has become the party of clerks and teachers.

In the 2010 elections, the biggest outside expenditure came from the American Federation of State, County and Municipal Employees, which pumped more than $87 million into races, all on behalf of Democratic candidates.

While President Obama and his party railed against the outside groups that were propping up Republican efforts, less noticed was AFSCME doing the heavy lifting for Democrats.

Democrats had certainly earned that support.

In August 2010, as voters were recoiling from deficit spending and Republicans were bashing Obama and his party as fiscally irresponsible, Democrats pushed through Congress a $26 billion state bailout package aimed at preventing government worker layoffs. Add that to the $160 billion that flowed to states from the 2009 Obama stimulus, and you see that Democrats have taken better care of state workers than probably any other group in the first two years of the Obama era.

Democrats argue that these subsidies are stimulative because they help prevent layoffs and trickle out into the larger economy as government workers spend their salaries. Maybe so, but that stimulus still involves taking money from one group of Americans (or from future generations of Americans) and giving to a select few.

Whatever the economics are, it’s just bad politics -- especially at a time when Americans are weary of a government that lives beyond its means.

And the issue is not going away anytime soon.

Some have been puzzled by the decision from Obama and the leaders of his campaign operation to become so deeply involved in the labor protests now gripping Wisconsin, Ohio and other cash-strapped states. It is unusual for a president to put his credibility on the line for a state budget battle, especially one so bitter and controversial.

Labor activists in the Midwest have painted an ugly picture of their movement, taking protests to lawmakers’ homes, shutting down schools and launching vicious personal attacks on Gov. Scott Walker, R-Wisc., and other political opponents.

But remember that Obama must win in states like Wisconsin and Ohio if he expects to have another term. And without well-funded government worker unions to provide ground troops and campaign cash for Democrats, victory in those swing states looks unlikely.

What Walker and his fellow fiscal hawks are doing is not just talking about trimming back very lavish benefits for government workers (Who wouldn’t like to have a $57-to-$1 match from their employers for retirement benefits and no-cost health insurance?). The GOP plan poses an existential threat to government unions and, by extension, the viability of the Democratic Party.

Team Walker is trying to strip government workers of the power to push for better pay, better benefits and more lenient work rules. Instead, pay hikes for state workers beyond the usual cost of living bumps would have to go before voters. More dangerous for big labor and the Democrats it supports is the plan to have the state stop collecting dues for unions.

The way it works now is that state workers’ dues are taken out on payday by the government, which then passes the dough on to union leaders. And since working in many state agencies or schools means you must join the union, there’s no choice but to pay up. The Walker plan would make government union dues voluntary, which would no doubt put a serious dent in the campaign coffers of state Democrats.

Walker is talking about defunding the Democratic Party in a key swing state and that’s cause for serious alarm for Obama.

As understandable as it is for Obama to seek to help his political benefactors and prevent a swing-state catastrophe in 2012, the deepening Democratic commitment to government workers is a perilous play.

A new survey from Clarus Research says that 64 percent of Americans don’t think government workers should be represented by unions. That’s a huge percentage for what until recent years was a political nonissue. But as union political involvement, public sector pay and deficits have all climbed into the stratosphere, voters have gotten wise to the game.

The average government worker now earns twice as much as his or her private-sector counterpart, with the gap doubling in past 15 years. Add in lush benefits and unparalleled job security, and you have created a privileged caste of workers and growing resentment among those who pay their salaries.

To get a sense of how the Democratic debt to government unions limits the party’s political possibilities, consider the current deficit debate in Washington.

For Democrats to get on the right foot with independent voters for 2012, this would be an ideal time to show some fiscal restraint – even of a symbolic nature. But the president and his party have instead proposed increased spending on government programs. Rather than co-opting the Republican message on fiscal discipline, Democrats are running the other way.

While Obama and his party may be sincere in their belief that more spending is needed to secure an economic recovery, they don’t really have much choice. Reduced spending means reduced government employment and government unions have chosen this as the moment to take their stand against a rising tide of fiscal conservatism.

When party coalitions get out of whack, there is always a political price to pay. Republicans, for example, have suffered in the past at different times for overreliance on big business and social conservatives.

And with many years of fighting between government workers and taxpayers, Democrats will find themselves on the losing side again and again.

Chris Stirewalt is FOX News’ digital politics editor. His political note, Power Play, is available every weekday morning at FOXNEWS.COM.