A RATHER OBVIOUS DECISION…. The big political story of the day yesterday was the Justice Department’s decision to try Khalid Shaikh Mohammed and four others connected to the 9/11 attacks in federal court in New York — and the apoplexy this decision generated among conservatives. Twenty four hours later, I’m still not clear on why the right is having such a breakdown.

The NYT had a good editorial on this today, calling yesterday’s announcement from the attorney general a “bold and principled step,” which “promises to finally provide justice for the victims of 9/11.”

Mr. Holder said those prisoners would be prosecuted in federal court in Manhattan. It was an enormous victory for the rule of law, a major milestone in Mr. Obama’s efforts to close the detention camp at Guantanamo Bay, Cuba, and an important departure from Mr. Bush’s disregard for American courts and their proven ability to competently handle high-profile terror cases. If he and Vice President Dick Cheney had shown more faith in the laws and the Constitution, the alleged mass murderers would have faced justice much earlier.

Republican lawmakers and the self-promoting independent senator from Connecticut, Joseph Lieberman, pounced on the chance to appear on television. Despite all evidence to the contrary, they said military tribunals are a more secure and appropriate venue for trying terrorism suspects. Senator John Cornyn of Texas, a former judge who should have more regard for the law, offered the absurd claim that Mr. Obama was treating the 9/11 conspirators as “common criminals.”

There is nothing common about them — or Mr. Holder’s decision. Putting the five defendants on public trial a few blocks from the site of the former World Trade Center is entirely fitting. Experience shows that federal courts are capable of handling high-profile terrorism trials without comprising legitimate secrets, national security or the rule of law.

That last point seemed to go largely unnoticed yesterday: we’ve done this before. KSM and his cohorts are, by all appearances, monsters. But the American system of justice is not only strong enough to deal with monsters, it’s done so many, many times.

Or, put another way, why are we even having this conversation? When we got Zacarias Moussaoui, we charged him, tried him, convicted him, and locked him up for the remainder of his miserable life. Republicans and Fox News personalities didn’t whine like children; it was simply a process that followed the rule of law.

The same is true of Ramzi Ahmed Yousef, Richard Reid, Sheik Omar Abdel Rahman, Jose Padilla, Ali Saleh al-Marri, John Walker Lindh, and Masoud Khan. The U.S. justice system has tried, convicted, and imprisoned hundreds of terrorists. Not one has ever escaped; not one has ever tried to escape.

And more to the point, when each was subjected to the criminal justice system, Republicans and their allies never complained. When they were sent to supermax facilities on American soil, no one whined about it or tried to scare the public.

It’s hard not to get the impression that conservatives are throwing a tantrum based on nothing more than the hopes that Americans won’t notice how foolish and cowardly they appear.

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.