Former FBI Director James Comey Chip Somodevilla/Getty images Paul Krugman on Wednesday said Republicans supporting President Donald Trump's firing of FBI Director James Comey are complicit in the undermining of the US democracy.

The Nobel laureate economist and New York Times columnist took to Twitter to express his belief that the Trump administration is no longer "legitimate" and to criticize any Republican defending Comey's firing.

"At this point we arguably do not have a legitimate president or administration," Krugman tweeted in response to a story about Democrats boycotting Senate committee meetings due to the firing. "We don't know the whole truth here. But the point is that Trump is trying to prevent us from finding out."

The White House said Trump had mulled firing Comey for some time due to what they painted as repeated missteps on the part of the director. Krugman didn't buy the White House's explanation, instead suggesting that Trump was trying to sabotage the FBI investigation into possible ties between the Trump campaign and Russian officials.

"This is a clear violation of the spirit of his oath of office, and probably the letter; he is setting himself above the law," Krugman said. "He deserves no presumption of innocence, and no deference to claims that he has the right to govern."

Krugman has been constantly critical of Trump's ties to Russia since his election, saying they undermine the legitimacy of his office. He also has said that he believes Comey's letter to Congress regrading the investigation into Hillary Clinton's private email server cost the Democratic nominee the election.

The economist also took issue with Republicans defending Trump. While a number of prominent GOP lawmakers such as Sen. Lindsey Graham and John McCain have taken issue with the move, there have been others that have said it was the right thing to do.

"And again, let's be clear: anyone helping with this obvious cover-up is deliberately being complicit with possible foreign subversion," Krugman tweeted. "Remember this any time any Republican, ever, pretends to be more patriotic than Democrats."

The Senate and FBI investigations into the Trump campaign's alleged Russian ties are expected to continue.