The salaries of Interior, Commerce, and Justice Department staff who are refusing to cooperate with the House could be on the line if they keep up their obstruction. That's the clear threat from House Oversight and Reform Committee Chairman Elijah Cummings.
The Maryland Democrat sent letters to eight current and former Trump administration officials informing them that if they continue to block two of the panel's investigations, they could feel the power of the Democrats' purse. "Please be advised that any official at the Department who 'prohibits or prevents' or 'attempts or threatens to prohibit or prevent' any officer or employee of the Federal Government from speaking with the Committee could have his or her salary withheld pursuant to section 713 of the Financial Services and General Government Appropriations Act," he wrote.
It is indeed within Congress' power to do that. It's also within its explicit power under the Constitution to conduct oversight. In the case of these inquiries—into the administration's push to have a citizenship question on the census and into whether Interior Secretary David Bernhardt and his staff are comply with federal record-keeping laws—the administration is either refusing or ignoring interview requests.