CEDAR RAPIDS -- U.S. Sen. Rand Paul questioned President Donald Trump's authority to unilaterally impose tariffs on other countries by edict, and applauded a federal court ruling blocking Trump from imposing sweeping tariffs on imports under an emergency-powers law.

The Kentucky Republican, speaking at Republican Party of Iowa fundraiser Thursday in Cedar Rapids, also sided with Elon Musk, calling proposed spending cuts outlined in Trump's "one, big beautiful" tax policy bill "wimpy and anemic."

Paul favors making tax cuts passed by Congress in 2017 during Trump's first term permanent, but said deeper spending cuts would be necessary to cut the federal deficit.

Musk announced earlier Thursday that he was leaving the Trump administration after spearheading efforts to slash the federal government. The tech billionaire's announced departure came one day after CBS released part of an interview in which Musk criticized the centerpiece of Trump's legislative agenda by saying he was "disappointed" by what the president calls his "big, beautiful bill."

The legislation -- which passed the House last week and heads to the U.S. Senate, which is expected to make changes -- includes $4.5 trillion in tax breaks and $350 billion in new spending on border security, mass deportations and defense.

It makes permanent the 2017 tax cuts, while temporarily adding new ones Trump campaigned on, including no taxes on tips and overtime pay.

To make up for some of the lost tax revenue and reduce the deficit, the bill makes changes to Medicaid -- the joint federal and state program that helps cover medical costs for low-income individuals, including the elderly and those with disabilities -- and the Supplemental Nutrition Assistance Program, also known as food stamps, aiming to reduce spending on the social safety net programs.

The cuts would largely be done by imposing work requirements on many of those receiving benefits and shifting more of the cost of SNAP and Medicaid to states.

Musk described it as a "massive spending bill" that increases the federal deficit and "undermines the work" of his Department of Government Efficiency, or DOGE.

"I think a bill can be big or it could be beautiful," Musk said, "but I don't know if it could be both."

A preliminary analysis by the nonpartisan Congressional Budget Office estimates the tax provisions would increase the federal deficit by $3.8 trillion by 2034, while the changes to Medicaid, food stamps and other services would result in $1 trillion in reduced spending.

"I'm kind of with Elon on this," Paul told reporters Thursday during the Iowa GOP fundraiser at Elmcrest Country Club.

He said he would approve cuts proposed by the Department of Government Efficiency to curb spending, but even then the savings found thus far are insufficient.

Musk's DOGE team initially set out to slash $2 trillion. DOGE has reported coming up with closer to $200 billion in cuts.

"As far as the spending cuts, I think they're kind of wimpy and anemic. I'd like more," Paul said.

He said everything has to be looked at when it comes to reducing federal spending -- including entitlement programs.

"Entitlements soak up everything," Paul said, referring to programs such as Medicaid, Medicare and Social Security that are mandatory and make up more than half of federal spending.

Trump has vowed not to "cut one penny from Social Security or Medicare, and I will not raise the retirement age by one day."

Paul also said Thursday he would not support Trump's sweeping domestic policy package unless the Senate removes a provision to raise the nation's debt ceiling by $5 trillion as part of the package.

He warned that the measure would add trillions in new borrowing with minimal offsets, undermining conservatives' commitment to fiscal responsibility.

"I've told the president I'm a 'no,' unless we separate out the debt ceiling. You take the debt ceiling off the bill, I'm pretty much a 'yes' on most of it," Paul told reporters.

Asked about push back from Iowa Republicans who want to see the president's agenda advance quickly, Paul quipped: "Iowans are too polite, aren't they?"

"Some have. Some come up and say, 'Support the president.' But I think I was elected also to be an independent voice, and I'm friends with the president," Paul said. "I do support the president. ... At the same time, we have some disagreements and I don't think it would be right to be quiet and not try to make the bill better."

'Tariffs are a tax, clear and simple'

Paul also has been a vocal critic of Trump's tariff and trade policies.

He applauded a federal court's ruling on Wednesday to block the president's use of emergency powers to impose sweeping taxes on foreign products, arguing that the Constitution gives Congress, not the president, exclusive authority to tax imports.

"Tariffs are a tax, clear and simple," Paul told Iowa Republicans gathered at the Cedar Rapids fundraiser.

A three-judge panel of the U.S. Court of International Trade ruled Wednesday that Trump overstepped his authority when he invoked the 1977 International Emergency Economic Powers Act to declare a national emergency and impose tariffs on imports from almost every country in the world, according to the Associated Press.

On Thursday, a federal appeals court allowed the president to temporarily continue collecting the tariffs under the emergency powers law while he appeals the trade court's decision.

Relying on the president to implement tariffs through emergency powers sets a bad precedent, Paul said, opening the door for future Democratic presidents to use emergency powers to push unfavorable legislation.

Even if one likes the tariffs, it shouldn't be the prerogative of one person, he said.

"I don't want the left to rule the country by emergency either," Paul said. "... No one should have that singular power that goes unchecked."

Paul said he gets text messages in all caps from Trump "telling me why I'm wrong about tariffs," eliciting laughs. He argues that tariffs create uncertainty for businesses and drive up prices for consumers.

He called Trump's justification for tariffs, based on trade deficits, an "economic fallacy." He argued that trade between countries is inherently mutually beneficial, and that focusing on trade deficits is an "artificial statistic" that doesn't reflect the true benefits of free trade.

Paul also pointed to resistance from various business sectors in his home state of Kentucky, including agriculture and bourbon production, who are negatively impacted by the tariffs.

"Ask the Iowa Farm Bureau what they think about trade," he said. "Twenty-five percent of your agricultural products are exports."

Paul said trade is proportional to prosperity, stating the only time that the trade deficit goes down is during a recession, "when we have less money ... and buy less stuff."

"If the President is successful in bringing tariffs down by sort of standing up and rattling the cage and being the bull in a China shop ... I'll be the first to compliment him," he said. "... But the proof is in the pudding, and I don't know which way it will go."

The Associated Press contributed to this story.