On Friday, Feb. 7, in a vindictive and retributive move to punish witnesses who testified against him in the House impeachment proceedings, President Donald Trump fired Lt. Col. Alexander Vindman, cirector for European Affairs for the United States National Security Council, and Ambassador Gordon Sondland, United States ambassador to the European Union.

Rep. Eliot Engel, D-New York, the chairman of the House Foreign Affairs Committee, pointedly observed: “This is shameful of course. But this is also what we should now expect from an impeached president whose party has decided he is above the law and accountable to no one.”

Was Engel’s fear correct? Put differently: Will Republican senators once again look the other way, placing party above principle and blindly following the lead of their president?

Sadly, it would appear so. Maine’s Republican Sen. Susan Collins had the unmitigated gall to tell reporters following the firings: “I obviously am not in favor of any kind of retribution against anyone who came forward with evidence.” Really? What a less than forceful rhetorical and uncourageous response. I wonder what she proposes to do about it.

Collins will not, I predict, enforce her disfavor with decisive action.

We have already witnessed Sens. Lamar Alexander, Lisa Murkowski and others admit that President Trump’s actions in the Ukraine scandal were wrong. They also incorrectly predicted the impeachment would change his behavior, preventing him from engaging in future illegal, inappropriate and self-serving actions that are not in the interest of the country.

In the case of Collins, I say with certainty: Like so many Trump sycophants, who weakly may declare they don’t like what Trump does but themselves fear his retribution, she will continue to be a lemming, acquiescing to Trump.  It will not matter what he says and does — or how unethical his words and deeds might be.

I trust that Maine voters are smart enough to see Collins for who she is. She failed to reject Brett Kavanaugh when he was nominated to be a Supreme Court justice. Her vote to subpoena witnesses and documents meant little given the predetermined outcome; many understood she was given a pass by Majority Leader Mitch McConnell on this vote to appease her constituents in Maine. And then she wouldn’t stand with fellow Republican Sen. Mitt Romney on the all-important vote to convict the president. It’s time for a senator from Maine who has the courage of her convictions.

Susan Collins, however, is not the only politician who should be condemned for failing to act. The time has come for voters across the nation to examine closely the failure of all their representatives and senators who didn’t hold President Donald Trump responsible for his despicable behavior. No matter how much some Americans may concur with Trump’s economic policies or appointments to the federal courts, we cannot excuse or permit the egregious wrong he has done.

Voting is a powerful democratic tool and, in this case, the last way to hold this president and his congressional enablers accountable. I hope Americans will exercise their right to vote, place principle above party and help end the current nightmare.

Richard Cherwitz, Ph.D., is the Ernest A. Sharpe Centennial Professor Emeritus, Moody College of Communication at the University of Texas in Austin and the founding director of the Intellectual Entrepreneurship  Consortium.