GOP presidential candidates have an easy answer for anyone concerned about the budget-busting impact of their tax cuts: Trust us.

Many Republican contenders are pairing tax plans that independent analysts say would cost trillions of dollars over a decade with vague assurances that they’ll put long-term clamps on spending for Medicare, Medicaid and Social Security. The GOP front-runner, Donald Trump, adds that it’ll be easy to find waste on the spending side.


But even some on the right say that Republican primary voters should be asking for more details from the candidates when it comes to offsetting their tax plans — especially given how deficits grew under the most recent Republican president, George W. Bush, and how little momentum there is now for deficit reduction.

“When the deficits were $1 trillion-plus a year, many Republicans were saying, ‘This is unsustainable. We’re going to have another financial crisis.’ And now they’re all coming up with these tax plans,” said Jim Pethokoukis of the American Enterprise Institute. “You should absolutely be skeptical if you’re a GOP voter.”

Republican candidates like Sens. Marco Rubio of Florida and Rand Paul of Kentucky, and Gov. John Kasich of Ohio frequently discuss tackling the federal debt as a moral imperative. Kasich has even called out his fellow GOP candidates on the debate stage, insisting their tax plans would push the country toward bankruptcy.

“I think the greatest threat facing future generations domestically is [a] $19 trillion debt for which there is no answer in place,” Rubio told Fox News in November.

Despite those rumbles of concern about red ink, Republicans are relying on much more expensive tax plans this election cycle.

The plans from former Gov. Jeb Bush of Florida and Sen. Ted Cruz of Texas would cut taxes by as much as $3.6 trillion over a decade, according to the Tax Foundation. Trump’s plan would cost as much as $12 trillion, and Rubio’s $4.1 trillion, the tax group also found.

Some of the GOP candidates have put a few details down on paper for how they would pay for their plans, at least in part. Cruz has said he wants to eliminate the Internal Revenue Service and the departments of Commerce, Education, Energy, and Housing and Urban Development.

Bush has proposed raising the eligibility age for Social Security and Medicare, as well as means-testing eligibility for those programs. And Rubio has embraced some of the same entitlement changes popularized by House Speaker Paul Ryan of Wisconsin.

“It's easy for everyone to say, ‘Cut spending.’ It's much harder and riskier to put out, chapter and verse, specifically the programs you would cut to stop bankrupting our kids and grand kids,” Cruz said at a GOP debate in November.

What Cruz didn’t mention is that enacting those sorts of wide-ranging policies — on both the tax and spending sides — would be difficult, if not impossible, without full GOP control in Washington, including a filibuster-proof Republican majority in the Senate.

It’s also proven a lot easier for presidents and lawmakers to talk about how they’ll cut spending than to actually do it. The highway bill passed in December is just the most recent example of how difficult it can be for Congress to push through real spending restraints. Lawmakers largely relied on funding gimmicks to pay for the bill, and backed away from some of the more controversial cuts they proposed.

Fiscal hawks worry that declining yearly deficits have sucked the urgency from efforts to make structural changes to policies on taxing and spending, just as entitlement programs are projected to become much more expensive. The Congressional Budget Office found that the federal government ran a $439 billion deficit in fiscal 2015, down from $1.4 trillion in 2009.

As if to prove the point, Congress just signed off on $680 billion in tax cuts in the year-end budget deal, though many of those incentives have been on the books for years and have been routinely restored on a short-term basis. And while GOP presidential candidates largely bashed the budget deal, Republicans generally didn’t complain about tax cuts that they said would allow businesses and individuals to keep more of their money.

“It’s much easier to talk about reducing debt and deficits when deficits are really high than when deficits are about to grow again,” said Loren Adler of the Committee for a Responsible Federal Budget.

When the U.S. was recording 13-figure deficits in 2010, President Barack Obama set up the Simpson-Bowles commission to get a handle on the problem, and tea party candidates were making the debt the centerpiece of their campaigns.

“I’ve had people, conservatives, that were very concerned about the deficit a few years ago,” Pethokoukis said. “They’re not so concerned these days. There’s just less momentum on that issue.”

For some Republicans, the yearly deficit figures are little more than a number. To them, the larger issue is ensuring that the federal government is as small as possible.

“I’d much rather have a big deficit with a small budget, than a small deficit with a big budget,” said anti-tax activist Grover Norquist.

Norquist has been critical of grand deficit bargains, like the one cut by President George H.W. Bush, saying the tax hikes from those agreements always go into effect, but the spending restraints never do.

But Norquist does think that entitlement changes like those conceived by Ryan could happen under a GOP president and would have staying power. Others aren’t so sure, noting that partisan gridlock has stopped any broad efforts at entitlement reform and that the 2016 election isn’t likely to produce a mandate big enough to change that.

“It's not that the two parties don’t have ideas that are real,” said Rohit Kumar of PricewaterhouseCoopers, a former top aide to Senate Majority Leader Mitch McConnell, “but there just hasn’t been a consensus between the White House and Congress.”