It’s never too early to start questioning the assumptions that guide presidential campaign coverage, whether they concern what candidates do and why they do it, what impact their decisions have, or how voters actually view the whole sordid extravaganza. And there are plenty of those just waiting to be unpacked and cast aside.

Today Lynn Vavreck, a political scientist writing for the New York Times, has what looks like some good news for Jeb Bush. She looks back at weekly polling data from 2012, and declares that if Mitt Romney moved to the right to win the primaries, the public seems not to have noticed. This might suggest that Bush — who has a couple of issue positions that conservative voters don’t like — is free to pander in the primaries to his heart’s content, without worrying about whether it might hurt him in the general election.

But I fear that Vavreck may be forgetting about a myth far more important than the one she’s trying to debunk. Before I explain, here’s the heart of her argument:

Because we have data every week, we can assess changes in average placements of the candidates over the course of the primaries and the general election. The data show that people’s views about the candidates’ ideologies didn’t move over the course of 2012. The lines are essentially flat.

For example, most people started and ended the election year believing, on average, that Mr. Romney was conservative, but not too much so. Any shifting, message-adjusting or pandering that Mr. Romney did during the primaries in 2012 did not hurt him in the general election by making him seem more conservative than he was earlier in the year, and it’s not at all clear it helped him in the primaries either. Mr. Obama, on the other hand, started the election year twice as far away from voters, on average, than Mr. Romney was and got farther away over the course of the year….

These three pieces of evidence — that Mr. Romney was thought to be no less conservative before the primaries than during or after them, that his average rating didn’t shift much at all during the entire year, and that he was ideologically closer to most voters than Mr. Obama — bust the myth that Republicans lost the 2012 election because of ideological shifts in the primaries.

This would appear to tell us that that Romney suffered not at all from his often comical attempts to pander to the Republican base in the primaries, and therefore such pandering poses no danger for Jeb Bush. But is that really true? To believe it, we’d have to believe that this poll question — asking voters to place a candidate on an ideological scale — captures the pandering phenomenon.

But there’s reason to believe it doesn’t. First of all, it’s possible that the pandering registered with many voters as something more like “Mitt Romney is running around telling people what they want to hear,” rather than “Mitt Romney is more conservative than he used to be.” It’s absolutely vital to remember that most Americans are not like those of us who care deeply about politics. Because politics isn’t something they think too much about, they don’t necessarily have a firm grip on even some of the most basic distinctions between the parties. Many don’t even know what it means for one candidate to be a “liberal” and another to be a “conservative.”

That may sound like an elitist thing to say, but it’s true. The National Election Studies has been asking respondents for many years which is the more conservative party. In recent years about two-thirds have been able to provide the right answer, which is actually an improvement over the 1980’s and 1990’s, when barely half could tell you. Think about that for a moment: a full third of Americans don’t know which is the “conservative” party.

It’s also vital to remember that when you look at all of them together, the public always perceives the Democratic presidential candidate to be farther to the left than the Republican candidate is to the right when they’re forced to answer the question. This is a phenomenon driven almost entirely by Republicans and Republican-leaning independents, who tend to describe the Democratic candidate as an extreme liberal, almost irrespective of who he actually is. The more partisan loyalties harden, the clearer the effect becomes. Here’s an excerpt from a 2003 article I wrote in my former life as an academic, citing NES data:

Republicans always perceive the Democratic candidate as much more liberal than Democrats and independents perceive him to be. Bill Clinton is the clearest case: while Democrats and independents placed him at about the same ideological position as most other Democratic candidates, in 1996 strong Republicans thought Bill Clinton was more liberal than previous strong Republicans had found Michael Dukakis, Walter Mondale, and even George McGovern.

That’s obviously not a judgment based in some kind of rational assessment of what a candidate stands for. More recently, you can see the phenomenon in this Gallup poll from the 2012 primaries. Democrats, Republicans, and independents all rated the Republican candidates about the same on an ideological scale, but Republicans saw Barack Obama as being far, far more liberal than Democrats or independents saw him. That ends up pulling the candidate’s overall rating toward the perception of Republicans. So when Vavreck tells us that Barack Obama was perceived as farther from voters ideologically than Mitt Romney was, she’s actually describing an old phenomenon that tells us little about what actually happened in 2012.

What’s the lesson here if you’re Jeb Bush — or, for that matter, some other Republican who feels the need to genuflect before conservative primary voters? It isn’t that pandering will have no cost. Wherever they put Mitt Romney on an ideological scale, voters rated him as less honest and trustworthy than Barack Obama, and his performance in the primaries probably had something to do with that. The lesson is probably that “ideology,” at least as political junkies understand it, is something that doesn’t matter all that much to most voters.

They aren’t going to say, “Well, I thought he was a 2.4 on the ideology scale, but I’ve concluded that he’s actually a 3.1, so I’m voting against him.” If Jeb Bush can pander and shift about ideologically while still convincing voters he’s a man of principle who can be trusted — no easy task — then if nothing else he’ll have one less thing to worry about. But if he can’t, then he’s much more likely to wind up like Mitt Romney.