Governor Christie of New Jersey thinks Mitt Romney will ace the debate tonight and turn the race upside down.  Let’s see.  Romney has had other game changing opportunities over course of the campaign the biggest being the Republican Convention.  What happened there?  His biographical film wasn’t done during prime time coverage.  Clint Eastwood talked to an empty chair and went over his allotted time.  Romney’s speech did not mention Afghanistan or American troops and, overall, was not very inspiring.

Tonight Romney will get another turn at bat.  The polls are still relatively close (more on them in a minute), but can the debate actually move the polls?

Ezra Klein writes in his Wonkbook this morning

Wonkbook’s number of the day: 0. That’s the number of recent elections that we can confidently say were decided by debates.

Gallup, for instance, reviewed their polls going back to 1960 and concluded they “reveal few instances in which the debates may have had a substantive impact on election outcomes.” Robert Erikson and Christopher Wlezien, in “The Timeline of Presidential Elections,” looked at a much broader array of polls and concluded that there was “there is no case where we can trace a substantial shift to the debates.” Political scientist John Sides, summarizing a careful study by James Stimson, writes that there’s “little evidence of [debate] game changers in the presidential campaigns between 1960 and 2000.

That’s not to say debates can’t matter, or that these debates won’t matter. The race remains close, and there are examples — 1960, 2000 and 2004, for instance — where  debates made a race more competitive, even if they didn’t clearly change the outcome. Simply closing the gap a bit would be a big win for Mitt Romney, if for no other reason than it would keep Republican donors invested in his chances going into the campaign’s final weeks.

One caveat to keep in mind, though: It’s not necessarily “the debates” that matter. It’s the debates plus the way the debates get spun in the media. There’s good evidence, in  fact, that the media’s spin is actually more important than the debates themselves. For more on that, read this article by Dylan Matthews, which is the best primer you’ll find on what we do and don’t know about what matters in presidential debates. The graphs are great, too

So going into the debate tonight (I’m writing this at about 7:30 am) where do the polls say we are?

Last night Nate Silver’s FiveThirtyEight blog posted these numbers for November 6:

Odds of Obama winning:  84.7%

Electoral Votes:  318.6

Popular Vate:  Obama 51.4 to Romney 47.5

Silver wrote

There were nine national polls published on Monday, which are listed in the table below. On average, they showed Mr. Obama with a 3.5 percentage point lead over Mr. Romney.

That’s smaller than the leads we were seeing in national polls last week, which seemed to be concentrated more in the range of a five- or six-point lead for Mr. Obama. It also suggests a smaller lead than recent state-by-state polls seem to imply.

So has the race already shifted back toward Mr. Romney some? Perhaps, but this is less apparent from the trendlines within these polls.

If you compare the nine surveys released on Monday against the last time they were published (in all cases, the comparison poll postdates the Democratic conventions), only four showed a shift toward Mr. Romney. An equal number, four, showed Mr. Obama gaining ground instead, while one poll remained unchanged.

In all cases but one, the shift was extremely modest — within one percentage point in one direction or the other. The exception was a new CNN national poll, which had Mr. Romney closing his deficit from six points to three points.

On average, however, the polls showed only a 0.2 percentage point gain for Mr. Romney — not a meaningful shift in either a statistical or a practical sense.

That is what I had when I went to bed last night.  I woke up to the NPR poll results.  The headline says

On Eve Of First Debate, NPR Poll Shows Romney Within Striking Distance

but the text says

The latest poll by NPR and its bipartisan polling team [pdf] shows President Obama with a 7-point lead among likely voters nationally and a nearly identical lead of 6 points in the dozen battleground states where both campaigns are spending most of their time and money.

However

More than 80 percent of respondents said they planned to watch the first televised clash Wednesday and one in four said the debate could influence their vote.

If you are a Romney supporter that may give you hope.  But remember, Governor Christie, he hasn’t come up to snuff at any big moments yet.  Maybe that means the debate is the time.

But for me, the most interesting thing to emerge from the NPR polling was this question.

On The Economy:

Now, thinking about the nation’s economy, do you believe the economy…

Source: NPR/Democracy Corps/Resurgent Republic

Credit: Padmananda Rama and Alyson Hurt / NPR

Almost half of those surveyed think the economy has bottomed and is starting to improve.  The economy was supposed to be Romney’s issue.

I’ll let Nate Silver have the last word.

But let me leave you with two themes that are at least reasonably well in line with the consensus of the evidence.

First, although it’s unclear whether Mr. Obama’s polls have already begun to decline, it’s more likely than not that they will tighten some between now and the election. The Nov. 6 forecast prices in some tightening while the “now-cast” does not, so sometimes they’ll have a different take on the polls.

Second, you should continue to watch the divergence between state polls and national polls.

As of Monday’s forecast, Mr. Obama was projected to win 22 states totaling 275 electoral votes by a margin of at least 4.7 percentage points — larger than his 4.1 percentage point projection in the national popular vote.

That speaks to a potential Electoral College advantage for him. But it’s important to watch the states that are just on the brink of this threshold, like Nevada and Ohio, or those where the polling has been varied, like New Hampshire.

Without Nevada, for instance, but with the other 21 states, Mr. Obama would be projected to a 269-269 in the Electoral College — which he would probably lose in the House of Representatives.

And his odds there will be a tie:  0.5%.

If you are an Obama voter you can be cautiously optimistic going into the debate tonight.