Of course, things might be very much the same without pre-election polling. Reporters don't always follow the numbers. Toward the end of 2006 and the beginning of 2007, for example, John McCain was repeatedly described as the Republican "front-runner," despite the fact that 53 of 57 national polls taken during that period showed him trailing Rudy Giuliani.
It's also possible that the worried-over "bandwagon" effect may not exist at all. What data we have from political scientists has been somewhat equivocal on the matter: Voters don't seem to be drawn inexorably toward the leader in yesterday's poll. If the bandwagon effect does exist, it might get canceled out by an equal and opposite inclination—the so-called "underdog" effect.
Pollsters concede that the effect of pre-election surveys is more clear-cut in the primaries, where voters are more inclined to vote strategically than they are in the general election. (It's no accident that the rise of public-opinion polling in the 20th century coincided with the movement toward primary elections.) By that token, a world without polling might help lesser-known candidates stick around. Meanwhile, the results of each individual primary election would become even more important than they already are. In our hypothetical scenario, the results in Iowa would be the first widely reported numbers of the entire race. The rankings established in Iowa would create a pecking order lasting all the way until New Hampshire—with no poll numbers in the meantime that might back up or deny the existence of any kind of "bounce."
In real life, pre-election polls seem to affect voter turnout in two ways. An apparent rout might make the outcome of an election seem like a foregone conclusion, leading voters to stay home. But polls showing a tight race tend to excite voters, and make them more likely to participate. We expect these effects to show up most acutely among young voters with a modest interest in politics—the kind who are interested enough to see the polls, but not fanatical about supporting their candidate.
If that's true, polling might have hurt Barack Obama's chances in New Hampshire. The polls leading up to Tuesday's Democratic primary suggested a decisive victory for the senator. But the polls may have depressed turnout among the young voters who were most likely to support him. (Independent voters might also have decided to vote for McCain, in what was thought to be the closer race.) So, in a world without pre-election polling, Obama would have had an easier time fending off a late surge from his opponents—but he'd have a harder time prevailing in close contests in the future.
The possibilities go on and on. But now it's your turn: What do you think would happen if our election cycle were spared the endless opinion polls? Would campaign coverage look any different? Or maybe the candidates themselves would change their messages, and their approach. …