‘PARTY PURGES’…. Every time a major media outlet insists “both sides” are guilty of trying to “purge” independent-minded members, an angel loses its wings.

The latest culprit is the Washington Post editorial board. The headline reads, “Party purges.”

The increasing polarization of the nation’s politics is fueling a blood sport in this election year: the ideological purification of both parties. Conservatives in Utah denied Republican Sen. Robert Bennett renomination last week. Liberals have targeted Arkansas Democrat Sen. Blanche Lincoln in a May 18 primary. […]

For many party cleansers, working across party lines constitutes treason. We agree that elected officials ought to be guided by principles that they are willing to fight for. But we also see a difference between fidelity to principle and dogmatism. […]

Is there a way to push back against the movement toward partisanship and paralysis — to carve out some space for those who strive to work across party lines in the national interest?

There’s quite a few problems here. The most obvious is the flawed effort to draw a parallel between Bennett and Lincoln. In the former, Bennett has been a reliably conservative senator from a reliably conservative state for nearly two decades. He was purged by the GOP’s right-wing base for only being rigidly dogmatic most of the time.

Lincoln, on the other hand, really has proven herself to be a disappointment to most Democrats, not because of a handful of isolated votes, but because of her departures from party priorities on a wide range of issues, over the course of several years. Utah Republicans had no such beef with Bennett.

There’s also a pragmatic angle — Bennett was a shoo-in for re-election, but was primaried for purely ideological reasons. Lincoln has struggled badly in the polls, prompting Dems who want to hold the seat to consider alternatives.

But it’s the bigger picture that the Post‘s editorial board gets especially wrong, with its description of “the ideological purification of both parties.” I realize that major media outlets have an unwritten rule — all criticism of Republicans has to include related criticism of Democrats, whether it makes sense or not — but the evidence to bolster the Post‘s observation is lacking.

Even if we concede that Blanche Lincoln is facing a competitive primary, at least in part for her lack of commitment to progressive goals, one primary for a vulnerable incumbent does not an “ideological purification” make. If Dems were seriously trying to drive those who strayed from the party line from the ranks, Blue Dogs would be under heavy fire, and the party wouldn’t have rallied behind Brad Ellsworth in Indiana and Charlie Melacon in Louisiana, neither of whom represent the bold, progressive wing of the party.

In contrast, there’s an actual “ideological purification” underway in the Republican Party. Florida’s Charlie Crist was deemed insufficiently right wing. So was Pennsylvania’s Arlen Specter and New York’s Dede Scozzafava. In Utah, Bob Bennett was handed a pink slip by his own party, and in Arizona, Sen. John McCain (R) is facing a tough primary challenge for nearly identical reasons.

Are we really witnessing “the ideological purification of both parties”? Of course not.

There’s no need to put a pox on both houses, when only one deserves it.

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.