If Republican lawmakers are able to end state and local tax deductions in their tax-reform bill, Americans will "never see it again," New York Mayor Bill de Blasio told CNBC on Friday.
The Senate GOP's tax plan, unveiled on Thursday, would eliminate federal deductions for state and local taxes. The House plan also calls for eliminating the deduction but allows a property tax deduction of up to $10,000. Tax analysts say the move could harm high-tax blue states, such as New York and California, where the state and local tax deduction is a major item.
"State and local deductibility has been in place since 1913. It has been something agreed upon by Democrats and Republicans throughout. Once it is gone, you'll never see it again," de Blasio told "Squawk Box."
He added that if the provision is removed, at least 100 million Americans would be subject to double taxation. "So, that puts downward pressure on state and local revenue," he said.
"The second problem is, the federal government then at any point can start raising the federal tax rate again. There's no prohibition," he said. "So, you lose the protection for homeowners, for everyday people, for middle-class people."
The Democratic mayor also says the U.S. needs higher growth rates, but the Republicans' tax bill is unlikely to facilitate that. Instead, growth comes from fixing our infrastructure, he said. "Our infrastructure is falling apart," de Blasio said, and "we need a strong federal government."
De Blasio was elected to a second term earlier this week, beating GOP state Assemblywoman Nicole Malliotakis and several third-party candidates. He is the first Democrat to win re-election as New York mayor since Ed Koch 32 years ago.
When asked whether he would seek a third term like Mike Bloomberg, de Blasio said "oh, no."
"I have differences with Michael Bloomberg and things I also really appreciate," he said. "I think it was a mistake to go for a third. Two-term limit. The people chose it. The people were right."