Senate majority leader Harry Reid and Senate minority leader Mitch McConnell just had an heated, lengthy exchange on the floor of the Senate over Reid's intention to use the so-called "constitutional option" at the beginning of the next Congress to change the rules of the filibuster using only 51 votes.

The specific changes Reid envisions aren't particularly dramatic: He wants to be able to make the motion to debate a bill -- but not the vote to pass it -- immune to the filibuster; he wants the time it would take to break a filibuster to be shorter; and he wants whoever is filibustering to have to hold the floor of the Senate and talk. None of these changes would alter the basic reality of the modern U.S. Senate, which is that it takes 60 votes to get almost anything done. In my view, that means they wouldn't do much to fix the Senate at all.

Nevertheless, McConnell is furious. But many of the arguments he was making on the floor Monday don't hold up to even the barest scrutiny.

1. "What these Democrats have in mind is a fundamental change to the way the Senate operates."

McConnell is referring to the Democrats' proposal to change Senate rules with 51 votes rather than 67. But his outrage isn't particularly convincing. As Senate whip, McConnell was a key player in the GOP's 2005 effort to change the filibuster rules using -- you guessed it -- 51 votes. As he said at the time, "This is not the first time a minority of Senators has upset a Senate tradition or practice, and the current Senate majority intends to do what the majority in the Senate has often done--use its constitutional authority under article I, section 5, to reform Senate procedure by a simple majority vote.”

Now, Reid, at the time, was steadfastly opposed to changing the rules with 51 votes. He condemned the idea as "breaking the rules to change the rules." So McConnell isn't the Senate's only inconsistent member on this point. But the fact is that McConnell was right the first time: The reason that Republicans believed they could change the rules with 51 votes in 2005 and Democrats believe they can do the same today is that they can.

2. "The minority voices the Senate was built to protect."

Oh, enough of this old saw. The idea that you need a two-thirds vote to change the Senate rules doesn't appear anywhere in the Constitution, and some scholars even think it's unconstitutional. It comes from the 1975 deal in which the total votes needed to break a filibuster was lowered from two-thirds of the Senate to three-fifths. As for the filibuster itself, it didn't emerge until decades after the founding of the Senate.

The American system of government was built to protect minority voices, but the Founding Fathers explicitly rejected designing the Congress around a supermajority requirement. In Federalist 22, Alexander Hamilton savaged the idea of a supermajority Congress, writing that “its real operation is to embarrass the administration, to destroy the energy of government and to substitute the pleasure, caprice or artifices of an insignificant, turbulent or corrupt junta, to the regular deliberations and decisions of a respectable majority.”

3. "Until now, you could say that protecting the rights of political minorities have always been a defining characteristic of the Senate. That's why members of both parties have always defended it, whether they were in the majority or the minority."

It's flatly false that the Senate has always rejected efforts to weaken the power of the filibuster. Before 1917, for instance, there was no way to end a filibuster at all. The Senate thought that excessive, and so they created the cloture process. Before 1975, the majority needed a two-thirds supermajority of the Senate (or at least of the senators who were present) to break a filibuster. That was brought down to three-fifths. Both of these reforms, by the way, are far more significant than what the Democrats are proposing, which wouldn't change the votes required to end the filibuster at all.

Meanwhile, it's particularly rich for McConnell to say that both majorities and minorities consider the filibuster sacrosanct, as he himself was a ringleader in the effort to eliminate the minority's ability to filibuster judicial nominees in 2005. "Even if one strongly disagrees with a nomination, the proper course of action is not to obstruct a potential judge through the filibuster but to vote against him or her," he said at the time. "Unfortunately, this obstruction necessitates that we restore these norms and traditions, and that includes through the use of the so-called 'constitutional option.'"

4. "If a bare majority can proceed to any bill it chose and once on that bill the majority leader, all by himself, can shut out all amendments that aren't to his liking, then those who elected us to advocate for their views will have lost their voice in the legislative process."

McConnell's complaint that Reid often doesn't allow amendments is legitimate, but unrelated to the rules changes under discussion. His complaint that Reid's proposed changes to the filibuster will mean the minority "will have lost their voice" is, however, absurd.

Reid is basically proposing two things: First, no more filibusters on the motion to move to debate a bill. Second, if you want to filibuster a bill, you have to actually take the floor of the Senate and speak. Reid's proposed changes might, in other words, end "quiet" filibusters, in which a bill is killed by a 60-vote challenge even though there's no debate on a bill. But so long as the minority was willing to hold the floor of the Senate and, well, use its voice, it would have all the power it currently has to filibuster a bill.

5. "[Reid] preferred to write legislation in the confines of his room rather than in the public eye, as he did most famously with the drafting of Obamacare."

After the Senate's Health and Finance committees drafted versions of the Affordable Care Act, Reid did combine them in private before bringing them to the floor. But the idea that the law wasn't written in the public eye is ridiculous. Both the committee processes were endless and, with the exception of Max Baucus's sojourn into the "Gang of Six" process, quite open, and Reid's effort to combine the bills mostly preserved the committees' work. After the law came to the floor, there was both a long period of public debate and an extremely open amendment process -- you can read the many, many amendments that got voted on here. As someone who had to cover that process and thus spent almost six solid months watching C-SPAN, I've little patience for those who suggest it was all conducted behind closed doors.

I want to be clear: Most every charge of hypocrisy that can be leveled at McConnell can also be leveled at Reid. And McConnell does have legitimate complaints, particularly when it comes to the ability to offer amendments. But the filibuster was not designed by the founding fathers, it has not been sacrosanct throughout the long history of the Senate, and its use today is not in any way comparable to its use 50 years ago. The biggest problem with McConnell's statements wasn't what he said so much as what he left out; namely, this graph, which shows the way the filibuster has gone from a rarely invoked minority protection to a constantly wielded supermajority requirement: