Republicans have demanded deregulation for decades. From Ronald Reagan's mandate to Newt Gingrich's Contract with America all the way to the present moment, GOP leadership has promised to initiate a massive rollback of the federal bureaucracy and a wholesale reduction of the regulations that ensnare businesses and ordinary Americans alike.

At times, the Republican Party has managed to make some headway, such as Reagan's tax reform program of simplification, or Gingrich's initial success in forcing Congress to give up its exemptions from federal regulation. For the most part, though, even the successes have been incremental. The federal workforce contracted in the 1990s mainly due to a significant drawdown in defense spending after the end of the Cold War, when defense workers were 49 percent of the federal workforce. Over the last 17 years, however, the federal workforce has grown again even though defense makes up just 35 percent of the total. That expansion includes four years when Republicans controlled both chambers of Congress and the White House (2002-2006), a point of frustration with conservatives — and the voters who sent them to Washington in the first place.

Until November, those voters had very little reason to believe that the promised dismantling of the regulatory regime in Washington would happen any time in the near future. Most believed that Hillary Clinton would win the presidential election and that Democrats would take advantage of a numerical advantage in Senate races to take back control of the upper chamber. Instead, Republicans beat the odds in both, holding onto the Senate and winning the White House, lifted by a populist wave that rejected the establishment in Washington, D.C. — including and perhaps especially its bureaucracies.

Now it's time for Republicans to either put up or shut up. It's time to rid the federal government of excessive regulations and dramatically reduce the federal workforce.

The White House budget proposal made it clear that the new administration wants to clean house. Most agencies other than those dealing with national security are up for deep cuts, not surprising from budget hawk Mick Mulvaney, now director of the Office of Management and Budget. Not all national-security efforts were immune to the axe either, as the proposal includes a 14 percent cut to the Coast Guard and significant cuts to the TSA and even Secret Service.

The White House has even begun to look outside of Washington, and even the U.S., for its cuts. Foreign Policy reports that the Trump administration wants to cut funding for United Nations programs by 50 percent. The U.N. has long been a target for conservatives who see it as a forum for diplomatic attacks on the U.S. and Israel. The cuts will come out of the State Department's Bureau of International Organization Affairs and could have major consequences for UNICEF and various peacekeeping missions.

Not all of the reductions will take place through the budget process. White House counsel Don McGahn told Time's Zeke Miller that he has a legal task force ready to undo decades of aggregation of federal responsibilities. McGahn sees this as a mission to reverse an unconstitutional blending of the powers of the three coequal branches of government in the myriad bureaucracies that exist in a twilight of agency law. "They make the law, they enforce the law, and then they decide who violates the law," McGahn told Miller, "destroying the constitutional separation of powers that was designed to protect individual liberty."

Also this week, Trump signed an executive order aimed at eliminating waste and duplication within the federal bureaucracies. It orders all Cabinet agencies to perform a "thorough examination" to identify programs and activities "where money is being wasted." Trump promised that the effort will result in "a detailed plan to make the federal government work better, reorganizing, consolidating, and eliminating where necessary." Eight years ago, Obama ordered a similar review, but found few reductions to make while continuing the gradual expansion of the federal workforce.

Clearly, the Trump administration takes deregulation seriously. But does the Republican Congress? And will they have the means even if they have the will to match Trump's efforts?

The budget process should give some clues on the answer. Most presidential budgets never make it into legislative language; even when Democrats controlled the Senate, Barack Obama's budget proposals were ignored. Trump's budget proposal, like most other presidential plans in the past, aims to draw some lines in the sand and frame the upcoming congressional debate over the FY2018 budget as appropriators begin to consider their options. But it is Congress, not President Trump, that writes the budget.

Trump's steep cuts have begun to open up fault lines on Capitol Hill, not just between moderates and conservatives but also between the House and Senate Republican caucuses. Representatives with federal operations in their districts have already begun to point out that some of the targeted programs provide employment and services for their own constituents. One aide called the proposal a "slash and burn" document, and told Reuters that the House caucus worries that they will be forced to back big reductions, only to have their feet cut out from under them by a far more moderate Senate proposal.

Those worries are not unsubstantiated, either. In the upper chamber, cuts to the State Department have already generated opposition among Republicans, including the man Trump most needs to seal the deal, Majority Leader Mitch McConnell. Even if Senate Republicans had more enthusiasm for the sharp spending cuts, they only have a slim majority. Democrats can use the filibuster on appropriations bills, which means that Republicans will have to compromise on spending levels enough to attract at least eight senators from across the aisle.

That may lead to a very unpleasant rift between the White House and Capitol Hill — or perhaps some satisfaction with incremental reductions in the budget process for the short run. Trump's Cabinet officials can gradually roll back staffing levels through attrition while congressional Republicans mull just how far they can go on cutbacks, and offer more reversals of regulatory growth in the previous administration through the Congressional Review Act.

The Trump budget could just be a "big ask," a technique in dealmaking that sets the parameters high enough for a stakeholder to maximize his potential successes. It's almost certainly an acknowledgment that a generation or more of promises to start making real cuts in the establishment's authority and power have to finally be honored, too. If Republicans can't implement those promises over the next two years with single-party governance in Washington, they may not have it for much longer than that.