Greg Sargent at The Plum Line has a couple of posts today about the boost of rhetorical adrenaline Democrats have gotten from the reflexive apology Rep. Joe Barton (R – Big Oil’s Pocket) issued to BP CEO Tony Hayward yesterday.  Saying that “Dems are determined not to let the Joe Barton story recede into the background, now that he’s retracted his apology,” Sargent notes:

The DNC has rapidly put together a new ad starring Barton that calls on Republicans to “stop apologizing to big oil” and says that if the GOP takes over the House, Barton will be in charge of the probe into the spill as chair of the Energy and Commerce Committee.

In a follow-up post, Sargent quotes Rep. Chris Van Hollen, chairman of the Democratic Congressional Campaign Committee (DCCC), promising this won’t be the end:

Joe Barton said publicly where the majority of Republicans stand on energy — protecting the big oil companies,” Van Hollen argued, pointing to the fact that the Republican Study Committee, which has over 100 members, has called the BP escrow fund a “shakedown.” … ”This goes way beyond Joe Barton. It’s part of a larger pattern where Republicans in Congress are on the side of big corporate interests.”

…”We’re going to be making the point again and again that Joe Barton’s comments on big oil [show] Republicans in the House stand on the side of big corporate interests against consumers and taxpayers.

In fact, Roll Call reports that the DNC has begun fundraising to support the new ad, and David Dayen notes in today’s Roundup that individual Democratic candidates are starting to blast their GOP opponents for remarks similar to Barton’s.

This visceral, who’s-on-your-side framing should be familiar to anyone aware of populist Democratic messaging over the years, and it’s a far sight more potent than the emotionally-drained “party of results” versus “party of no” approach that DNC chairman Tim Kaine was threatening promising a couple of months ago.  (A hint, guys: If unemployment is still hovering between 9.5% and 10% come November, don’t expect that “party of results” stuff to have much resonance.)

But however refreshing it is to hear Democrats forthrightly characterizing Republicans as what they are, it’s equally sobering to think of what it took to reach this point — an epic ecological catastrophe, extended so long that the president’s poll numbers began to be dragged downward, pushing his party to find a potential angle of counterattack.  Before that, it was all about mealy-mouthed “bipartisanship,” pragmatism, and attempts at partnering with politicians and interest groups diametrically opposed to the needs and wants of ordinary Americans.

So, unless Democrats are willing to revisit a more effective economic stimulus program, a public option for health insurance, and a host of other issues, it’s hard to see this rhetorical shift as anything but a conversion of convenience, scheduled to expire just after this fall’s elections.