Poor Arlen Specter. He can hardly catch a break. But at least he's remaining calm.

From last week's rancorous town hall meetings across Pennsylvania, to his grilling Friday at the Netroots Nation conference in Pittsburgh, the Democrat-turned-Republican-turned-Democrat senator faced skeptical, even antagonistic crowds.

Perhaps that's because no one trusts a political turncoat/partisan lapdog.

Or perhaps it's because the politically diverse citizens speaking out on the Obama administration's biggest domestic agenda item care very passionately about the outcome -- and want to find out where their famously fence-straddling senator now stands.

The only ones giving Mr. Specter the benefit of the doubt were the surprisingly unskeptical media, who took at face value the senator's repeated and demonstrably false claims that he's still seeking to occupy the middle ground.

But you can hardly blame the reporters and editorialists for their lapse: They have been very busy wringing their hands over the health-care protesters' boorishness and the threat this poses to civil discourse.

Funny, but they weren't concerned about the boorishness -- to put it mildly -- of Bush-era protesters. They didn't even report on it.

In its excellent "Best of the Web" feature, The Wall Street Journal picked up Thursday an essay by Bill Sammon, Fox News' Washington managing editor, detailing the violent and obscene protest that greeted George W. Bush on a Portland, Ore., visit in 2002. While those actions and images -- graphically described on the Fox Web site -- were witnessed by New York Times and Washington Post reporters, they went completely unreported, Mr. Sammon notes. Yet these two news outlets have made health care protesters' behavior the primary focus of their coverage this time around (as have many other news organizations).

So ... vulgar and violent anti-Bush protesters get a pass, but worried senior citizens raising their voices at town hall meetings threaten noble American traditions? Not really, of course, but they do threaten Arlen Specter's re-election prospects -- if he ever makes it past primary voters like the liberal bloggers he faced Friday.

It's a wonder, really, as CNN reported on one of his town hall appearances, that Mr. Specter "remained calm most of the time."

To be sure, the year has certainly given him plenty of practice: He made national headlines in April by switching parties after his February vote for President Obama's stimulus package alienated his Pennsylvania Republican base. Some polls showed him losing the 2010 primary to his 2004 challenger, former Rep. Pat Toomey, by sizable margins.

The Democratic leadership embraced Mr. Specter with open arms, endorsing him-- from the White House on down -- as their 2010 Senate candidate, and a Rassmussen poll had Mr. Specter leading Mr. Toomey by 11 points in June.

But that was before Democratic Rep. Joe Sestak of Delaware County announced he'd flout his party and challenge Mr. Specter. And, more ominously, it was before the Democrat-controlled Congress's leadership on health care reform ignited public outrage.

Where does the battered senator stand now? A Rassmussen poll released Thursday shows him leading Mr. Sestak in the primary by 13 points but trailing Mr. Toomey in the general election by 12 points. It's a dramatic shift.

Where does Mr. Specter stand? The left-wing bloggers who warmly applauded him Friday nonetheless said they don't trust him. A moderator questioned his leadership, saying, "He'll do what he's told, which is what he did with the Republican Party." The back half of that assertion is laughably wrong.

Where, really, does he stand? He told the Post-Gazette editorial board he still occupies the middle ground, but his votes tell a different tale.

According to a Congressional Quarterly examination of his voting record, released Thursday, Mr. Specter's "party unity score in his brief Democratic Senate career is higher than any party unity score he amassed in his 28 years as a Republican senator."

While "[h]e averaged a 58 percent party unity score from 1981 through 2008 and exceeded a 70 percent party unity score just once" -- in 2003, interestingly, going into his last primary -- he has scored 91 percent as a Democrat.

Until July he knew he had to, if he wanted to defeat Mr. Sestak, whose party unity score is a whopping 97. But August's passionate health care protests have changed the political landscape. It's hard to see how the Senate's most famous shape-shifter can woo staunchly left primary voters without further alienating the bigger and boiling ranks of conservatives and moderates.

Last week "Specter remained calm most of the time," they tell us. Given the daunting re-election challenge ahead, this is probably, for him, the calm before a storm of his own making.