Most of the gaffes from Mitt Romney's presidential campaign can be pinned on the candidate himself. But the error that "may go well beyond a momentary embarrassment and become a campaign-defining disaster" came from longtime trusted aide Eric Fehrnstrom, says Joe Klein at TIME. Talking to CNN after Romney's big victory in the Illinois GOP primary this week, Fehnstrom argued that Romney would have no problem pivoting toward the political center after the primaries, because the general election campaign is "almost like an Etch A Sketch. You can kind of shake it up and restart all of over again." Romney's GOP rivals and the Democratic National Committee immediately seized on the remark, saying it proved once and for all that Romney is a politician with no true conviction. What can we learn from Romney's Etch A Sketch mishap? Here, five lessons:

1. The worst gaffes confirm existing narratives
Every politician makes the occasional verbal flub, but in the hierarchy of political gaffes, "playing to type — or even appearing to play to type — is the kiss of death," says Chris Cillizza at The Washington Post. The Etch A Sketch line is likely to stick around because it's an easy metaphor for a larger doubt people already have about Romney: That he "lacks any core convictions and that he will say and do whatever it takes to win."

2. Conservatives were right not to trust Romney
If there was any doubt that "Romney would betray the Right," well, "the dirty secret is out now," says Brent Budowsky at The Hill. This gaffe vindicates conservatives' reluctance to rally behind a candidate who will eventually throw them and their principles under he bus. The Right was actually just starting to buy into Romney's claim that he's a conservative masquerading as a moderate, and that "they're in on the con," says Jonathan Chait at New York. This gaffe gives conservatives ample "grounds to wonder if they're the suckers."

3. Political campaigns can't be too honest
The Etch A Sketch moment is just another example of Team Romney "failing to hide its cynicism," says New York's Chait. The campaign's political calculations are "totally sound," even obvious: Adjusting your campaign to fit different audiences is Politics 101. But the strategy "works a lot better if you pretend you're advancing actual core beliefs." There's a reason guys don't hit on girls at the bar with lines like "I am going to feign strong interest in what you're telling me in hopes of establishing an emotional connection that will loosen your sexual inhibitions."

4. "Momentum" is a fragile thing
The Etch A Sketch line might still be an issue in the general election, but Romney has to get through the primaries first, says Michael Falcone at ABC News. Fehnstrom stuck his foot in his mouth at the height of "what was supposed to be a triumphant day," with the Illinois win and an endorsement from Jeb Bush promising to finally end the GOP race. "The ensuing mockery completely obliterated" those hopes, and once again, Romney "will have to rely as much on money — instead of momentum and message — to pull himself through another primary night."

5. The gaffe's importance is being oversold
This Etch A Sketch "flap-a-doodle" mostly "reveals just how shallow the GOP primary race has become," says Catherine Poe at The Washington Times. The U.S. faces serious challenges. Would it be too much to ask the candidates to stick to the issues instead of silly gotcha gimmicks? Besides, YouTube is full of clips of Romney shifting his position, says Ezra Klein at The Washington Post. "If Fehrnstrom had called in sick Wednesday, the public would still have been presented with evidence that Romney is not a sincere man."