Grover Norquist of Americans for Tax Reform is no fan of a proposed “robot tax” touted by Microsoft founder Bill Gates. Daniel Chaitin reports for the Washington Examiner.

“A robot tax is a particularly stupid tax. It is a tax on productivity — a tax on growth,” Grover told the Washington Examiner in an email exchange.

Gates made the suggestion during an interview with Quartz in February, in response to the number of jobs being lost to automation. “If a human worker does $50,000 of work in a factory, that income is taxed,” he said. “If a robot comes in to do the same thing, you’d think that we’d tax the robot at a similar level.”

But Norquist, founder and president of Americans for Tax Reform, criticized the idea as a “tax on the future.”

He isn’t the first to mock Gates’ idea. For example, former Treasury Secretary Lawrence Summers asked in a Washington Post opinion piece, “Why pick on robots?”

Adjusting to automation is becoming an increasingly important tax issue, in both the U.S. and abroad. Debate on the matter just wrapped up in the European Union. In February, the European Parliament rejected the idea of a robot tax on firms that own them to support or retrain workers who lost out on employment due to robots.

When asked about how this might work in the U.S., Norquist quipped: “Why not tax consumers who refuse to buy high platform shoes, or hot pants, or non-black dresses or last year’s fashion?”

“Consumers ultimately decide what gets bought and they are therefore responsible for all unemployment. Tax those guys with long hair who put barbers out of work. Or book readers who bankrupt Disney films,” he said. “This is a rabbit hole too stupid down which to run.”