Joe Lieberman has joined forces with Scott Brown to introduce legislation that would let the government strip terror suspects of their citizenship.

Surprisingly, GOP leader John Boehner isn’t on board with this idea, but Hillary Clinton is.

WASHINGTON — Proposed legislation that would allow the government to revoke American citizenship from people suspected of allying themselves with terrorists set off a legal and political debate Thursday that scrambled some of the usual partisan lines on civil-liberties issues.

The Terrorist Expatriation Act, co-sponsored by Senators Joseph I. Lieberman, independent of Connecticut, and Scott Brown, Republican of Massachusetts, would allow the State Department to revoke the citizenship of people who provide support to terrorist groups like Al Qaeda or who attack the United States or its allies.

Some Democrats expressed openness to the idea, while several Senate Republicans expressed concern. Mr. Brown, who endorsed aggressive tactics against terrorism suspects in his campaign for the late Senator Edward M. Kennedy’s seat, said the bill was not about politics.

“It reflects the changing nature of war and recent events,” Mr. Brown said Thursday. “War has moved into a new dimension. Individuals who pick up arms — this is what I believe — have effectively denounced their citizenship, and this legislation simply memorializes that effort. So somebody who wants to burn their passport, well, let’s help them along.”

What is this legislation really about, though? Is there really a pressing need to revoke the citizenship of certain types of suspects?

The reality is that the American criminal justice system has done a damned good job of dealing with terrorists, from the 1993 World Trade Center bombers to Timothy McVeigh. Hundreds of people are in prison in the US for terror-related crimes, and some have even been executed. There’s never been a high profile terrorism case in which defendants escaped justice by exploiting their rights as citizens.

The motivation for taking away the citizenship of terror suspects seems to be solely so we don’t have to worry about their pesky constitutional rights any more. And note: the bill deals with suspects, not even people who’ve been convicted of any crimes.

That slope isn’t just slippery, it’s frictionless.