Polls ahead of November's midterm elections universally indicate that Democrats are in for a rough ride — the question is how rough. That is where the polls differ, sometimes by a huge margin. With election day, Nov. 2, nearing, pollsters are shifting from interviewing registered voters to those they deem to be "likely" voters in an attempt to better predict the results. Here is a look at three big new polls asking people how they would vote in a so-called generic ballot — pitting an unnamed Republican vs. an unnamed Democrat — and what the numbers mean:

Gallup: A GOP mega-tsunami among "likely voters"
The result: Republicans lead Democrats, 46 percent to 43. But if turnout proves low, the GOP margin could balloon to 18 points (56-38).
The reaction: Wow, says John Fund at The Wall Street Journal. That "low turnout" margin is a "stunning" advantage the likes of which the GOP "has never been seen in Gallup surveys." If that scenario happens, "some word more cataclysmic than 'tsunami' would be needed for the Democratic losses." Those are no doubt "terrifying numbers for Democrats," says Nate Silver at The New York Times. An 18 percent lead would give the GOP more than simple control of the House — they would win a strong majority by picking up 86 seats! But take that with a grain of salt. Statistically, there is just a 1 in 200 chance of such a GOP landslide. 

Rasmussen: The Dems are narrowing the gap
The result: Republicans 45 percent, Democrats 42 percent. The GOP led by six points in the same poll a week ago, and by 10 points two weeks ago.
The reaction: It is rare to see Democrats getting a boost from Rassmussen, says Steve Benen at Washington Monthly, as its polls are notorious for skewing Republican and getting trumpeted on Fox News. But even for those who routinely dismiss Rasmussen, these numbers are worth noting, because they show a steady improvement for Democrats "when comparing Rasmussen data against other Rasmussen data." Sure, says Jay Cost at The Weekly Standard, but the difference between Gallup and Rasmussen largely stems from their disagreement on how many "undecideds" are left. Lots of those are independents, and Gallup and Rasmussen agree that "Republicans are running away with the independent vote." So Democrats should not take too much comfort from this poll.

Newsweek: A contrarian shocker
The result: Democrats 48 percent, Republicans 43 percent. That is among registered voters — and the Democrats' lead grows to 8 points among "definite voters."
The reaction: This is "weird," says Josh Marshall at Talking Points Memo. Newsweek polls are historically "relatively friendly" to Democrats, but this goes against what everyone else is saying. It narrows the Talking Points Memo poll average to just a 2-percent GOP lead. This "either means nothing or everything and most likely something in between." Don't let Newsweek's numbers get your hopes up, Democrats, says David Freddoso at The Examiner. Newsweek's sample had more Democrats than it should have, plus it assumed "a lower GOP turnout than in 2008." This poll is just wrong.