From Bloomberg:

“I don’t think that’s had an impact on the market at the moment,” Mnuchin told reporters at the Capitol on Tuesday. “The debt markets are one of the most liquid markets in the world and are reacting very well.”

The article continues:

The Treasury Department said last week that the U.S. would boost note and bond sales for the first time since 2009 this year to finance rising budget deficits, fueled in part by the tax overhaul President Donald Trump signed into law at the end of last year.

JPMorgan Chase & Co. strategists last month lifted their forecast for net new Treasury issuance in 2018 by about $100 billion, to around $1.42 trillion, after the passage of the tax bill. Net sales in 2017 totaled about $550 billion.

I might add that in addition to credit market impacts, fiscal stimulus at what appears to be close to full employment threatens higher interest rates (in a standard IS-LM model) and higher inflation (in a conventional aggregate demand-aggregate supply framework).