When Democrats invoked the so-called “nuclear option” last week, changing Senate rules to let President Obama's judicial nominees go through with simple majority votes, their opportunism was evident.

Just a few years earlier, they had mounted and defended filibusters against former President George W. Bush's judicial nominees.

Suddenly, they took the opposite end of the same argument, abolishing such filibusters when it served their goals.

Sen. Harry Reid, D-Nev., and then-Sen. Barack Obama, D-Ill., had once asserted, respectively, that the “nuclear option” would “ruin our country” and “put an end to democratic debate.”

One might almost conclude that these gentlemen habitually make charged statements that they don't believe at all – for example, that “if you like your health plan, you can keep your health plan.”

But no matter how naked this power grab was, conservatives should not mourn it. This new post-nuclear era may present the first true opportunity in decades to turn back the tide of Big Government.

The real precedent that the Senate set last week has nothing to do with judicial filibusters, but rather with the way they were abolished. A two-thirds majority is now no longer required to change Senate rules.

Sen. Carl Levin, D-Mich., a six-term liberal retiring next year, voted against the nuclear option precisely because he understood that this “is not a one-time action.”

Speaking on the Senate floor, he noted, “If a Senate majority demonstrates it can make such a change once, there are no rules which bind a majority, and all future majorities will feel free to exercise the same power – not just on judges and executive appointments but on legislation.”

Big Government requires a level of institutional stability and inertia that the Senate filibuster helped provide. It is a major reason why, even as conservatives succeed with a multitude of state-level reforms, they repeatedly come up empty in Congress, where a simple majority is rarely sufficient to effect real change.

But Washington's inertia and stability have just been fatally weakened. Take the labor unions – the major impetus behind what happened last week.

Already weakened by declining membership, they feared that a conservative D.C. Circuit Court of Appeals would jam them in several upcoming cases, and they embraced the nuclear option as a way of installing Obama nominees quickly.

But unions have benefited perhaps more than any other liberal interest group from the Senate's supermajority requirements.

Senate inertia has long kept out of reach the modernization, reform or repeal of the outdated liberal laws that prop the unions up – the Davis-Bacon Act, the Jones Act and the National Labor Relations Act itself. That could soon change.

That's only the beginning. It's hard even to imagine the Bush era without the filibuster, but it might have gone quite differently.

To be sure, the 60-vote threshold directly thwarted only a handful of conservative priorities – medical liability reform, interstate competition for small group health plans, permanent lower tax rates and repeal of the so-called “death tax.”

It also blocked a law that would prevent the transport of minor children, unbeknownst to their parents, across state lines for abortions.

But the list gets a lot longer if you count measures that never reached the floor, which the supermajority requirement turned into impossible dreams.

Social Security reform, tax reform and reform of the Endangered Species Act are the just the tip of the iceberg here.

The newly majoritarian Senate will pose new risks for everyone - conservatives included. But given that the status quo in federal law has been well to the left of common sense for so long, conservatives have a lot less to lose from this new world the liberals have just made possible.

DAVID FREDDOSO, a Washington Examiner columnist, is the former Editorial Page Editor for the Examiner and the New York Times-bestselling author of "Spin Masters: How the Media Ignored the Real News and Helped Re-elect Barack Obama." He has also written two other books, "The Case Against Barack Obama" (2008) and "Gangster Government" (2011).