John Sununu explains for Boston Globe readers why U.S. Senate Majority Leader Harry Reid made a mistake in endorsing a change to longstanding Senate filibuster rules.

For nearly 225 years, the principle of open and unlimited debate has worked well in the US Senate. Yes, there has always been plenty of pontificating and histrionics; and deliberation can be painstakingly slow. That however, is by design. The Senate was meant to balance the impulsive nature of the House and put all states on equal footing. An open debate and amendment process encourages consensus and protects against the tyranny of the majority.

But as majority leader, Reid has been a unique and fierce opponent of open debate. Yes, of course Democrats claim Republicans have mounted a “record” number of filibusters, but Reid’s machinations behind the scenes tell a different story. Scheming to avoid tough votes for vulnerable Democrats, he has repeatedly called bills to the Senate floor, blocked all amendments, and immediately moved to cut off debate. Republicans of every stripe have opposed these “cloture” votes, in the belief that an honest, fair process demands the right to offer amendments.

Reid and his supporters argue that the new rule change limiting the filibuster will apply only to certain presidential nominations. At best, that’s wishful thinking. More likely, it reflects supporters’ naivete, ignorance of history, or plain sophistry. By excluding Supreme Court nominees, they concede that there is no principle at stake here — just political expediency. In all likelihood, Democrats didn’t have 51 votes within their caucus to make the change for the Supreme Court, so they just took what they could.

In just the same way, a future Senate majority, Democratic or Republican, will take what it can, eventually eliminating the filibuster for legislation and Supreme Court nominees as well. We will be left with a Senate ruled at all times and everywhere by a simple majority vote. Bipartisanship will be unnecessary, a mark of weakness rather than strength. Lost amid the rubble will be the center, the concept of coalition building, and the need for compromise.