Every few weeks, a well-intentioned, high-profile pundit argues that what American politics really needs is a third party, one which will presumably tend to the needs of centrists and the American mainstream. And every few weeks, these pundits make the same mistake.

Today, it’s Matt Miller, a contributing editor here at the Washington Monthly, arguing that “neither party trusts us enough to lay out the facts and explain the steps we need to take to truly fix things.”

As always in a democracy, better leadership starts with better followership. New groups such as Americans Elect and No Labels are showing the way, building the infrastructure and local networks for a new politics of problem-solving. But we’ll never mobilize the “far center” without an agenda around which people can rally. To move this ball forward, I’ve taken a crack at a policy-heavy version of the third-party stump speech we need, to suggest what it would sound like if an independent candidate called seriously for a “decade of renewal.”

Here’s that third-party stump speech Miller has in mind. I give him credit for being fairly specific — too often, third-party proponents don’t bother — and there’s plenty to like in Miller’s vision. This platform for the imaginary independent candidate includes noteworthy details, but the general sketch would include: bold spending on job creation, raising teacher salaries, responsible “hawkishness” on foreign policy, guaranteeing health care coverage for the uninsured, raising taxes (especially on the wealthy) as part of a larger tax reform initiative, reforming entitlement programs with their long-term fiscal stability in mind, and adding new layers of accountability for Wall Street.

This, Miller says, would be “different’ from Democrats and Republicans. He’s half-right — it’s “different” from what one of the major parties has in mind.

Look, I realize much of the American mainstream is inclined to throw up its arms in disgust, denounce both parties, and find the idea of a new alternative appealing. But pretending that the Democratic Party’s agenda and President Obama’s vision simply don’t exist isn’t helpful. There are structural, electoral, and procedural hurdles between what Dems want and what Dems can get, but the fact remains that nearly everything Miller wants to see from an independent candidate is already being offered by the current occupant of the Oval Office.

Miller’s pieces seem to acknowledge this, but argue that the Democratic agenda needs to go even further down the road they’re already on. But as Greg Sargent explained very well, this is an overly-convenient dodge these pundits rely on too heavily.

Given this inconvenient overlap between the Democratic Party and the positions these commentators imagine for their fabled third party, they are constantly forced to find ways in which the Democratic Party has not gone far enough in adopting those positions…. But you can forever continue raising the bar in this fashion.

Indeed, even if you concede the existence of such failings on the part of Dems, it’s still fair to ask why these commentators are so reluctant to acknowledge the vast overlap that does exist between Dems and their imagined third party — and to explain why we need a third party despite that massive overlap. Let’s face it: At bottom, the calls for a third party are founded on a dodge — a refusal to acknowledge that the Democratic Party is far closer than the GOP to the fabled ideological middle that they themselves have defined as the space that only a third party can claim.

This becomes all the more frustrating when one considers the frequency with which it comes up.

Thomas Friedman recently presented a platform he believes is absent from the discourse, but neglected to mention that it was practically word-for-word the same platform Obama already supports. Inexplicably, Friedman did it again last week.

In June, David Brooks longed for some bold candidate to step up and present a “Hamiltonian/National Greatness” agenda, and then presented a wish list that might as well have been copy-and-pasted from an Obama speech. Also note, more than 100 business leaders have rallied behind Starbucks CEO Howard Schultz’s pledge to stop making campaign contributions unless policymakers adopt a series of economic measures, apparently unaware that the White House already wants all of those same measures.

Paul Krugman summarized the problem nicely: “I know that admitting that Barack Obama is already the candidate of centrists’ dreams would be awkward, would make it hard to adopt the stance that both sides are equally at fault. But that is the truth.”

Update: Milller took the time to put together a thoughtful and detailed response to the criticisms. I disagree with his conclusion, but it’s worth reading.

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.