Trump and GOP face a tougher tax sell to Dems than Reagan did, ex-Treasury official says

Kimmitt: Treasury Department has the most consequential agenda

President Donald Trump and GOP leaders on Capitol Hill should aim to get as much support as possible from Democrats for their tax reform plan, but that's going to be difficult in this environment, said Robert Kimmitt, who served the three previous Republican administrations.

"When we did tax reform in the second term of the Reagan administration and put our proposal out in 1986, it was roundly criticized by everybody. And we knew, therefore, it was going pass," Kimmitt told CNBC's "Squawk Box" on Tuesday. Currently a public policy advisor at the law firm WilmerHale, Kimmitt had served as general counsel to the Treasury during the Reagan administration.

House Republicans, led by Ways and Means Chairman Kevin Brady and Speaker Paul Ryan, have crafted a broad tax overhaul package, including a reduction in corporate taxes.

Trump generally supports the idea of tax reform and campaigned on similar principles, but the White House has made no firm commitments on how to get it done.

One aspect of the GOP plan includes a border tax, a political lightning rod, which has been roundly criticized by companies that rely heavily on imports, such as retailers.

"In '85 [and] '86, we did tax reform. We did that largely behind the scenes and then put it out," Kimmitt said. "They are going to be doing it [now] in a more open fashion. In this political environment, that will be tougher."

Among his other government positions, Kimmitt had served as deputy Treasury secretary under President George W. Bush and as U.S. ambassador to Germany under President George H.W. Bush.