Looking back to early August, it now seems funny that Sen. Scott Brown’s campaign website would trumpet a collection of quotes mocking Democrats for giving Elizabeth Warren a prime speaking position at the party’s Charlotte convention.

“What’s unclear is whether Warren is the ideal surrogate to deliver that red-meat rhetoric in front of a national television audience,” wrote the National Journal’s Josh Kraushaar, while NBC legacy hire Luke Russert tweeted, “Hard to see the benefit of #Dems giving Warren a prime time slot at DNC considering she’s such a lightning rod for criticism.”

The conservative Daily Caller mocked, “No, seriously. They’re putting the woman who gave us ‘You didn’t build that’ front and center,” while Fox News confidently declared the move a disaster: “It was by any measure a bold move by Democrats, considering Warren gave the talk last year that is credited with inspiring Obama’s controversial remarks earlier this month on America’s businesses. Those remarks have since fueled a wave of GOP attack ads.”

Of course, a funny thing happened at the conventions. All the “We Built That” attacks at the Republican National Convention fell flat, with polling showing little bounce for Mitt Romney. But when Democrats, including Warren, doubled down on their populist message, they were rewarded with a significant bump in the polls.

“President Obama believes in a country where we invest in education, in roads and bridges, in science and in the future, so we can create new opportunities,” Warren said at the convention. “We grow [the economy of the future] with opportunity. And we build it together.” That’s the message that helped Obama expand his lead in both national and battleground polling, and which has now led Warren to pull ahead of Brown here in Massachusetts.

Public Policy Polling went from a 49-43 Brown lead a month ago to 48-46 Warren on Sunday, Sept. 16. Western New England College just checked in with a 50-44 Warren lead, after showing Brown leading big earlier this year. Suffolk gave Warren a 48-44 lead Monday night, Sept. 17 after showing Brown leading 48-47 in May. The Republican consulting firm Kimball Political had Brown winning 49-43 immediately before the GOP convention, and leading just 46-45 after the Democratic one.

Those aforementioned pundits truly failed to understand the appeal Warren brings to the campaign. Rather than a disaster for the Democratic Party and Obama, it’s clear Warren’s keynote boosted her chances and contributed to a dramatically successful Democratic convention. They saw her off-the-charts fundraising as a sign of overt liberal partisanship, but her appeal doesn’t lie in partisan rhetoric.

Rather than simply talk about the struggle between the middle class and a system rigged against them, she has lived that fight. As the architect and first head of the Consumer Financial Protection Bureau, she has been a lone figure reining in a financial sector run amok. In fact, the nascent agency scored its biggest victory recently by forcing Capital One to refund $150 million in fees directly into the accounts of 2.5 million customers, in addition to another $60 million in fines.

Yes, this is the kind of action that inspires liberals, but it’s also the kind of practical populism that wins broad-based public support. Warren’s speaking slot was validation that today’s Democratic Party is no longer afraid of its beliefs or disapproval from Beltway hacks like Luke Russert.

Voters got a look at both the Warren message and the selfish Republican one, and the polling couldn’t be clearer on which resonated best with voters.

Markos Moulitsas is founder and publisher of Daily Kos and a columnist at The Hill.