Ask anyone what the theme of the 2008 campaign was.

Most people will give a one-word answer: Change. Depending on their political ideology and opinion of President Obama, they will use 'change' differently, but there is little dispute that 'change' was the overarching theme that put Barack Obama in the White House in a landslide election.

'Change' was then-Sen. Obama's campaign theme, and it came to dominate and define that election. In addition to his campaign's organizational prowess and his political talent, Barack Obama won the White House in large part because his campaign's central theme framed the entire presidential election.

That is the power of framing. Broad framing defines the perception of the other candidates, the issues, and the messages. In 2008, eventually even John McCain tried to run as a change agent, terming the Republican ticket as a "team of mavericks." A candidate who can frame the election in their own terms has an incredible advantage, and often ends up winning. If you are framing the debate, you are defining the terms of the issues.

It's the one reason that Bernie Sanders, despite being a one-issue candidate who fell consistently far behind in the delegate count, has been able to stick it out this far, raising a lot of money and earning a very respectable amount of votes and delegates. Although not overwhelming success, it is undeniable that Sen. Sanders has had great success in his attempt to frame this election - at least the Democratic contest - as a referendum on the big progressive wishlist as opposed to practical, deliverable agenda.

"It's too late for establishment politics", Sen. Sanders is fond of saying. That is him driving home the appeal that progressives should demand everything and cross the bridge of delivering it when and if we got there. Hillary Clinton, who took the approach of "a progressive who gets things done", based her message of continuing the landmark reforms President Obama has achieved while expanding on them with pragmatic, achievable benchmarks.

Clinton's message - her frame - has been that we need to concentrate on results while Sanders' frame is that the focus needs to be on the wishlist. Clinton has driven home the point that she has the experience and qualifications to deliver results on domestic and foreign policy objectives, while Sanders has whipped the idea that he has the boldness of vision to achieve an unprecedented revolution in favor of the progressive wishlist.

Both candidates have been relatively successful in driving their points within their respective frames, but neither has been particularly effective in breaking through the others' frame and establishing their own in its place.

Until now. Until Bernie Sanders' universally panned interview with the New York Daily News exposed critical gaps in the Senator's understanding of his key campaign issues and raised serious questions about his ability - or even willingness - to address specific policy agenda. Corners of the national media began to question Bernie Sanders' qualification to be president, given his shallow, stump-speech only understanding of many critical issues.

This isn't the first time Bernie Sanders' qualification and experience has been questioned in the race for presidency. Sometimes directly, but more often indirectly, many have raised the point that even though Bernie's message of the whole progressive wishlist was attractive, Hillary Clinton was better qualified to get things done from the Oval Office.

Not much was different this time. Except one thing.

This time, Bernie Sanders bit. With the press finally beginning to pick up on the dangerous lack of depth and Newtown plaintiffs repudiating his close association with the gun lobby, Bernie Sanders finally felt the need to establish himself as qualified.

He jumped into that debate rather bizarrely. He claimed that it was Hillary Clinton who was not qualified to be president.

"Secretary Clinton appears to be getting a little bit nervous," he told a crowd in Philadelphia. "And she has been saying lately that she thinks that I am 'not qualified' to be president. Well, let me, let me just say in response to Secretary Clinton: I don't believe that she is qualified, if she is, through her super PAC, taking tens of millions of dollars in special interest funds. I don't think that you are qualified if you get $15 million from Wall Street through your super PAC."

Hillary Clinton has never said Bernie Sanders is not qualified to be president, and legally, Hillary Clinton has no more control over any super PAC supporting her than Bernie Sanders has over right wing super PACs spending ad money on his behalf.

But don't get bogged down into those details. That's just gravy on top of this very substantive gift the Sen. Sanders has now given Sec. Clinton. And that gift is that Bernie Sanders has left behind his own message frame and entered hers: the debate over qualifications.

Qualifications are what Hillary Clinton is running on. Even in states Hillary Clinton has lost in the primary, the Democratic electorate by and large believe that she is the qualified, experienced, "resume" candidate.

Even Bernie Sanders has conceded that point once or twice, and a Gallup poll released last month showed that almost 50% of Clinton voters see experience and qualifications as her strong suit, compared to only 5% of Sanders supporters believing the same about him. Sanders was stronger on his voters believing he cares about them. A Quinnipiac poll found that nationally (not just among Democratic voters), 62% of voters believe Hillary Clinton has the right experience, while only 46% said the same about Sanders. Hillary Clinton has dominated newspaper editorial endorsements, which put a high value on qualifications.

In other words, qualifications is Hillary Clinton's turf. It is her argument to voters - an argument voters nationwide have pretty well bought into. It has stuck because it's true. Adding up her experience in formulating policy as First Lady, her tenure as a US Senator, and her work as Secretary of State for President Obama, Hillary Clinton is the most qualified, experienced candidate to run for president perhaps ever, and there is no way to make an attack on her there. In fact, some would claim that the same resume has been hampering her a little, as Bernie Sanders on the Democratic side and Donald Trump for the Republicans have painted her as an establishment, insider candidate, even if in reality, Bernie Sanders is the ultimate insider politician.

When there is no way to shake your opponent's strength because it is both patently obvious and has taken shape in the minds of voters, you try to do two things: paint that strength as weakness (which is what Trump and Sanders have tried to do by running as anti-establishment), and create your strength as the more important factor.

Although Barack Obama was prolifically qualified as a candidate in his own right - having been a community organizer, a law professor, a state legislator and a US Senator who had deep knowledge, achievements and interest in critical issues - he was smart not to match experience with Hillary Clinton in 2008 even though she had not yet had the run as Secretary of State under her belt yet. Who would have won that fight would make an interesting hypothetical, but the way Barack Obama won was by establishing the promise of change as the most important factor.

Bernie Sanders went that way for a while, and it seemed he was pretty good at message discipline. Yes, we mocked him for being a noun-verb-Wall-Street candidate, but even that mocking came about due to his message discipline of being able to turn everything into a problem of Wall Street, however ridiculously.

No more. Bernie Sanders is now gearing up for a fight he cannot win, and he's using equipment he's never been good at operating. Bernie Sanders cannot win the qualifications debate against Hillary Clinton. Trying to argue that point makes him look desperate, ludicrous and plain silly. But more importantly, it knocks him out of the frame he has been trying to establish, with at least some success.

Just as saying "don't think of an elephant" cannot help but make the listener think of nothing but an elephant, saying "Hillary Clinton is not qualified" can't help but make people think of qualifications, and Hillary Clinton's strength as the qualifications candidate. Putting a "no" before a frame does not negate that frame; it reinforces it.

Up until now, Clinton had had to play in Sanders' frame at least to some degree, making the argument that while she has the same goals (the wishlist) as Sanders, she has the practical experience to deliver and not to over-promise. The moment the debate, with Bernie Sanders' willing consent, became about qualifications (rather than a wishlist), the tables were turned. Bernie Sanders wading into a qualifications death match with Hillary Clinton will frame the national conversation in a way that makes people think of qualifications first when it comes to deciding their presidential preference.

My guess is that this is the outcome the Clinton campaign had been hoping for but never imagined in their wildest dreams would come so easily.