Just before summer recess, Congress voted to approve expansion of the terrorist surveillance program, an action that had the left wing raging bitterly last week.
Regardless of the merits of the lefties' position, or lack thereof, the issue has brought them to that frustrating point -- one familiar to, say, anti-abortion activists and Republican strategists -- where ideological purity collides with political reality.
The Bush administration had requested changes to the warrantless surveillance program to keep up with suspected terrorists' technological advances, especially the increased use of Internet phone services.
After classified security briefings, enough Democrats joined the Republican minority to pass the bill.
"Progressive and liberal groups and left-leaning blogs are furious, tossing around fighting words like 'spineless,' 'craven' and 'weak'," The New York Times summarized Wednesday.
What's missing in the anti-war purists' rants is a recognition of practical politics. In the contest of ideas raging around this war, as with other emotional issues such as abortion, the purists forget that when it comes time to vote, they will always get less than they think their cause merits.
They forget that most of us live comfortably in the "yes, but" zone, and we're the mass of voters that elected officials who want to stay elected must appeal to.
With abortion, an ever-growing American majority expresses distaste for the practice and a desire to see it more restricted -- yes, but they think banning it is unreasonable or unachievable.
Purists argue that taking an innocent life for any reason is wrong, and they promote candidates in the primaries who share this point of view. The issue has drawn otherwise Democratic voters to the Republican Party for almost three decades. But progress on the broader national stage, vote by vote by court case, has been slow.
Will the war on terror affect the Democrats the same way? At the grass-roots level, candidates' popularity ratings depend increasingly on repudiation of the Iraq war and of virtually any Bush policy in the broader fight against terrorism.
Left-wing activists rejoice over polls showing more and more Americans of both major parties weary of the war in Iraq. They assume this translates into support for their whole cause, so they can't comprehend how Congress could fund the surge or refuse to end the war or, now, hand the administration a win on surveillance -- especially since, as the Times noted, "the president [is] low in the polls."
No story on a Bush administration effort would be complete without the writer or broadcaster reminding Americans that a majority of them give President Bush low marks for job performance.
What's missing from these reports -- and what is particularly helpful in analyzing the terrorist surveillance vote -- is the fact that congressional ratings are even lower.
An AP/Ipsos poll from early July shows Mr. Bush's approval rating at 33 percent and Congress' at 24. By a smaller margin, opinion polls from Gallup, CBS/New York Times, NBC/Wall Street Journal and Newsweek also give Mr. Bush the popular advantage. All of them also show the president's numbers inching upward and Congress' steady or declining.
Left-wing activists and some journalists may not take this big piece of political reality into account, but elected Democrats sure do. All four Democratic senators who are presidential candidates -- who must curry the favor of left-wing activists and particularly the vitriolic blogosphere -- voted against expanding the surveillance program.
But those who voted for it are, as one frustrated local activist described them to me, "freshmen reps and others who don't have safe seats." Exactly. They lack the protection of incumbency so their votes must reflect the desires of their constituents -- not the activists, the "yes, but" masses.
Some voters followed the issue closely enough that there were no "buts" about the expansion: "Foreign-to-foreign calls and e-mails passing through American data networks? Have at 'em."
Others may have settled for, "Yes, I'm disappointed in the president, but Congress is worse, so give Bush what he wants."
Congressmen did a little yes-butting too: Yes, they couldn't miss left-wing activists' demands for pure anti-Bush votes but, as a spokesman for Senate Majority Leader Harry Reid put it: "Everyone who heard the [classified security] briefings ... agreed that the intelligence community did not have what it needed."
You could argue that they chose broad electoral support over partisan purity tests. Or you could say they viewed the expansion not as a win for the administration, but as a national security tool that a majority of Americans want -- maybe to help win a war they don't want.
Either way, that's political reality. It's too messy and too crucial to leave to the purists.
Ruth Ann Dailey can be reached at firstname.lastname@example.org or 412-263-1733.