The Senate tax bill is stuffed with provisions for special interests. Car dealerships would be able to fully deduct interest on loans, thanks to Sen. Rand Paul, R-Kentucky.
Meanwhile, an amendment by Sen. Ted Cruz, R-Texas, allows parents to pay for K-12 private school tuition using tax-free college savings accounts. Republican Sen. Rob Portman of Ohio, where big private jet companies are based, reportedly got them exempted from a levy known as a "ticket tax."
Some of the biggest winners in the bill arewhich pass the income through the owners who don't pay corporate taxes. Instead, they file that income on their individual tax returns, reports CBS News correspondent Julianna Goldman.
The Senate's tax bill lets certain oil and gas firms take advantage of the lower tax rates on pass-through businesses. The provision was added by Sen. John Cornyn, R-Texas, whose campaign has received more than a million dollars in contributions from the oil and gas industry in 2013.
"We're going to find some really stinky stuff in here that we didn't know," Sen. Angus King, I-Maine, said on "Face the Nation." King said there's a lot he and his colleagues still need to learn.
Real estate developers like President Trump and the Trump Organization, would also benefit from the tax cuts for pass-through businesses, according to former Obama tax policy adviser and Center for American Progress senior fellow Seth Hanlon.
"He is sort of the poster child here of the type of wealthy business person or wealthy billionaire who's going to get a massive windfall from this tax cut," Hanlon said.
The president's budget director Mick Mulvaney defended the measures.
"Yeah, you're going to change the way we treat, again, pass-through entities. But a lot of the deductions are gone," Mulvaney said.
The bill would also open up part of the to drilling, a cause championed by Sen. Lisa Murkowski, R-Alaska. She was one of the last GOP holdouts on the tax plan.
"This is good for Alaska, but more importantly, it's good for the country," Murkowski said.
Another amendment spared cruise lines from paying higher taxes. Sen. Dan Sullivan, R-Alaska, said it would help communities and businesses that rely on tourism.
"This is just you know slapdash, sloppy, un-transparent lawmaking, and I frankly have never seen anything like this," Hanlon said.
The bill is also notable for what's not in it: a research and development tax credit appears to have been accidentally eliminated. More surprises are expected as lawmakers actually finish reading a bill they've already passed.