President Trump’s budget chief defended the administration’s first budget proposal on Wednesday, underscoring the importance of economic growth and putting “taxpayers first.”

Office of Management and Budget Director Mick Mulvaney told lawmakers on the House Budget Committee that he went “line by line” through the federal budget, and asked himself whether government officials could “justify” costs.

“Can we justify this to the folks who are actually paying for it?” Mulvaney asked the bipartisan panel. “I don’t think people are willing to pay for as much government as they are.”

Mulvaney’s appearance on Capitol Hill is just one of four planned for Wednesday, as Trump Cabinet officials, including Treasury Secretary Steven Mnuchin, Education Secretary Betsy DeVos, and Agriculture Secretary Sonny Purdue, also will testify before House panels to defend the president’s budget.

The administration’s Fiscal Year 2018 budget is titled “A New Foundation for American Greatness,” but Mulvaney told lawmakers it could have had a different title: “We could have called it the ‘taxpayer first’ budget.”

The president’s plan pushes to increase economic growth to 3 percent, and balance the budget within a 10-year window. Many on the left have called the growth rate “unreasonable,” but Mulvaney said that “Trumponomics” could “get us there.”

“I have news for you: If we don’t get to 3 percent growth, it’s unlikely we’ll ever get a balanced budget again,” Mulvaney said, asking lawmakers “how pessimistic can you be” to think 3 percent is impossible. “If that’s where you are, don’t accept it -- 3 percent growth is not something we should talk about, but something that should drive everything.”

But Democrats on the committee slammed the administration, and charged that much of the cuts would rip apart the nation’s “social safety net.”

Rep. Pramila Jayapal, D-Wash., told Mulvaney that cuts to food stamps, payments to the disabled, and other programs are “astonishing and frankly immoral.”

But Mulvaney stood by the administration’s position, and slammed the “certain narrative” that Republicans “don’t care about poor people,” standing by the confidence social safety nets give people to “take risks and go out on their own.”

“This is a moral document and here’s the moral side: If I take money from you and have no intention of ever giving it back, that’s not debt -- that is theft,” Mulvaney said. “If I take money from you and show you how I can pay it back to you -- that is debt.”

Mulvaney added: “We don’t want to measure compassion by the number of programs we have and the number of people on them -- true compassion is the number of people we want to try to get off of those programs and get back in charge of their own lives.”

The administration’s budget proposal remained consistent with Trump’s campaign promises, leaving Medicare and Social Security untouched.

But the plan does cut almost $3.6 trillion from an array of benefit programs, domestic agencies and war spending over the coming decade -- an almost 8 percent cut -- including repealing former President Barack Obama’s health law, cutting Medicaid, eliminating student loan subsidies, sharply slashing food stamps, and cutting $95 billion in highway formula funding for the states.

But Mulvaney ensured that the administration would not take “any deserving person off any program,” saying the administration looks at it from difference perspectives: “folks who receive benefits and folks who pay for benefits.”

Other cuts include $63 billion to pension benefits for federal workers by eliminating cost-of-living adjustments for most workers and requiring employees to make higher contributions. In agriculture, the proposed budget would limit subsidies to farmers, including for purchasing crop insurance, a move already attacked by farm state lawmakers.

Mulvaney addressed cuts to Public Broadcasting Service, home to the widely-adored Sesame Street.

“I can assure you Big Bird makes more money than everybody in this room,” Mulvaney said, ensuring PBS is a “for-profit cooperation” that does “very well.”

But the budget does feature a major domestic initiative -- a six-week paid parental leave program headed by Ivanka Trump that would be designed and financed by the states through cuts to unemployment insurance, at a projected cost of $25 billion over the next 10 years.

“We’ll try to get the country back to a healthy economy again, get people working again, and get people optimistic of the country again,” Mulvaney said. “If you’re under 30, you’ve never had a job in a healthy American economy -- the optimism that comes from that is what this nation is all about.”

The Associated Press contributed to this report.