Not only did FiveThirtyEight's Silver pick all 50 state winners in the presidential race, he also beat out his polling aggregator rivals for sheer margin of accuracy. 
 
 FiveThirtyEight blogger and statistician Nate Silver. (Credit: CBSNews.com) 
 
 While there's already been whole swimming pools of ink devoted to the Election Day prediction performance of polling aggregators like FiveThirtyEight blogger Nate Silver, CNET is ready to hand out one more round of kudos to the king of the quants. 
 
 By now, anyone following the presidential election knows that Silver successfully predicted the winner in the race between President Barack Obama and former Massachusetts Gov. Mitt Romney in all 50 states. That performance was one for the ages, earning him worldwide admiration and validating a polling aggregation model that had drawn mockery and ire from many pundits. 
 
 This CNET chart shows that, among polling aggregators, FiveThirtyEight's Nate Silver was more accurate than anyone on Election Day. (Credit: Data by Daniel Terdiman/CNET) 
 
 But Silver wasn't the only one to do exceptionally well in the prediction department. In fact, each of the five aggregators that CNET surveyed yesterday -- FiveThirtyEight, TPM PollTracker, HuffPost Pollster, the RealClearPolitics Average, and the Princeton Election Consortium -- successfully called the election for Obama, and save for TPM PollTracker and RealClearPolitics handing Florida to Romney, the aggregators were spot on across the board when it came to picking swing state victors. 
 
 Read: The post-election tech tally: Winners and losers 
 
 Still, even within the club of those who used computational analysis of thousands of national and statewide polls to peg the outcome of the election, someone had to be the most accurate. And a CNET examination of each aggregator's performance reveals a single winner -- unsurprisingly, Silver. 
 
 In addition to picking the winner in all 50 states -- besting his 49 out of 50 slate in 2008 -- Silver was also the closest among the aggregators to picking the two candidates' popular vote percentages. All told, he missed Obama's total of 50.8 percent by just four-tenths of a percentage point (50.4) and Romney's 48 percent by just three-tenths of a point (48.3) for an average miss of just 0.35 percentage points. HuffPo Pollster and RealClearPolitics tied for second with an average miss of 0.85 points. 
 
 In preparing to make these comparisons, CNET surveyed 11 swing states. In the end, Silver was closest to the final margins among the candidates in seven of them and also had the best overall record, missing by an average of just 1.46 points in the 11 states. TPM PollTracker was second with the closest predicted margins in three states, and the second-best average margin, 1.80 points. 
 
 It is worth noting that while Silver's final pre-election calculations showed a tie vote in Florida, he still predicted a 50.3 chance that the president would prevail in the Sunshine State. 
 
 The performances by Silver and his fellow polling aggregators should be sounding alarm bells in the halls of long-venerated pollsters like Gallup -- which, by the way, predicted that Romney would win the national popular vote by a point. 
 
 For the Nate-haters, here's the 538 prediction and actual results side by side twitter.com/cosentino/stat... -- Michael Cosentino (@cosentino) November 7, 2012 
 
 But the situation does create a bit of a chicken-and-egg problem. While the results of pollsters like Gallup and many of its competitors are looking increasingly suspect in the face of more accurate predictions by Silver and other aggregators, and while some may begin choosing to ignore those traditional polls, the aggregators could not do what they do without the standard polling systems. 
 
 In the meantime, even Silver may need to tip his cap to someone who seems to have done an even better job at prognosticating the final presidential election results. In a blog post today, dailyKos founder Markos Moulitsas noted that he had predicted exactly the final Electoral College vote totals and reported an average margin in the swing states that was less than Silver's or that of any aggregator. Moulitsas' methodology? A savvy but seemingly manual reading of last-minute pre-election polls. Maybe the quants don't have all the answers after all. 
 
 Correction, November 8, 4 p.m. PT: The above chart originally misreported the number of points by which TPM PollTracker was off in Florida. The correct figure is 1.7 points. ||||| The term “momentum” is used very often in political coverage — but reporters and analysts seldom pause to consider what it means. 
 
 Let me tell you what I think it ought to mean: that a body in motion tends to stay in motion. That is, it ought to imply that a candidate is gaining ground in the race — and, furthermore, that he is likely to continue to gain ground. 
 
 As a thesis or prediction about how polls behave, this notion is a bit dubious, especially in general elections. In races for the United States Senate, for instance, my research suggests that a candidate who gains ground in the polls in one month (say, from August to September) is no more likely to do so during the next one (from September to October). If anything, the candidate who gains ground in the polls in one month may be more likely to lose ground the next time around. 
 
 (Where might there be clearer evidence for momentum, as I’ve defined it? In primaries, especially when there are multiple candidates in the race and voters are behaving tactically in choosing among them. But there is little evidence of it in general elections.) 
 
 The way the term “momentum” is applied in practice by the news media, however, it usually refers only to the first part of the clause — meaning simply that a candidate has been gaining ground in the polls, whether or not he might continue to do so. (I’ve used this phrasing plenty of times myself, so I have no real basis to complain about it.) 
 
 But there are other times when the notion of momentum is behind the curve — as it probably now is if applied to Mitt Romney’s polling. 
 
 Mr. Romney clearly gained ground in the polls in the week or two after the Denver debate, putting himself in a much stronger overall position in the race. However, it seems that he is no longer doing so. 
 
 Take Wednesday’s national tracking polls, for instance. (There are now eight of them published each day.) Mr. Romney gained ground in just one of the polls, an online poll conducted for Reuters by the polling organization Ipsos. He lost ground in five others, with President Obama improving his standing instead in those surveys. On average, Mr. Obama gained about one point between the eight polls. 
 
 Photo 
 
 This is the closest that we’ve come in a week or so to one candidate clearly having “won” the day in the tracking polls — and it was Mr. Obama. 
 
 The trend could also be spurious. If the race is steady, it’s not that hard for one candidate to gain ground in five of six polls (excluding the two that showed no movement on Wednesday) just based on chance alone. 
 
 What isn’t very likely, however, is for one candidate to lose ground in five of six polls if the race is still moving toward him. In other words, we can debate whether Mr. Obama has a pinch of momentum or whether the race is instead flat, but it’s improbable that Mr. Romney would have a day like this if he still had momentum. 
 
 The FiveThirtyEight model looks at a broader array of polls — including state polls — in order to gauge the overall trend in the race. 
 
 Our “now-cast” also finds a slightly favorable trend for Mr. Obama over the course of the past 10 days or so. Mr. Romney’s position peaked in the “now-cast” on Friday, Oct. 12, at which point it estimated a virtual tie in the popular vote (Mr. Obama was the projected “winner” by 0.3 percentage points). As of Wednesday, however, Mr. Obama was 1.4 percentage points ahead in the “now-cast,” meaning that he may have regained about 1 percentage point of the 4 points or so that he lost after Denver. Mr. Obama’s chances of winning the Electoral College were up in the FiveThirtyEight forecast to 71 percent on Wednesday from 68.1 percent on Tuesday. 
 
 It’s not yet clear how much of this, if any, has to do with the final presidential debate in Florida this Monday, which instant polls regarded Mr. Obama as having won. Instead, it’s been more of a slow and unsteady trajectory for him, with Mr. Obama often taking two steps forward but then one step back. It’s also not out of the question that the apparent trend just represents statistical noise. 
 
 At the same time, there is more reason to take a potential change in the polls seriously if it is precipitated by a news event like the debate. The tracking polls that were released on Wednesday contained only one full day of interviews that postdated the Florida debate. If the debate moved the needle toward Mr. Obama, it should become more apparent in the coming days. 
 
 The battleground state polls that came in on Wednesday were generally very close to our model’s current projections. For instance, there were three Ohio polls published on Wednesday; one showed a tied race there, while the other two showed Mr. Obama ahead by margins of two and five points.That’s pretty much what you’d expect to see out of a trio of Ohio polls if Mr. Obama’s lead there were about two points, which is where our model now has it. 
 
 Some of the polls, especially the Time magazine poll which had Mr. Obama five points ahead in Ohio, seemed to set off a lot of discussion on Twitter, as though people were surprised that Mr. Obama still held the lead there. 
 
 But these polls are really nothing new. Since the Denver debate, Mr. Obama has held the lead in 16 Ohio polls against 6 for Mr. Romney. In Nevada, Mr. Obama has had the lead in 11 polls, to Mr. Romney’s 1. Mr. Obama has led in all polls of Wisconsin since the Denver debate, and he has had five poll leads in Iowa to one for Mr. Romney. 
 
 Part of the confusion (and part of the reason behind the perception that Mr. Romney is still gaining ground in the race) may be because of the headlines that accompany polls. 
 
 We’re still getting some polls trickling in where the most recent comparison is to a poll conducted before the Denver debate. We should expect Mr. Romney to gain ground relative to a poll conducted before Denver. (Mr. Romney may have lost a point or so off his bounce, but he has clearly not lost all of it). But it isn’t news when he does; Mr. Romney’s Denver gains had long ago become apparent, and priced into the various polling averages and forecast models. 
 
 The question, rather, is whether Mr. Romney is gaining ground relative to the post-Denver polls — or if, as Wednesday’s polls seemed to imply, the race instead may have ticked back slightly toward Mr. Obama. ||||| GOP presidential candidate Mitt Romney leads President Obama by 3 points nationally, according to the closely watched Gallup daily tracking poll. 
 
 Romney takes 50 percent to Obama's 47 in the poll of likely voters, released Thursday. That’s unchanged from Wednesday’s daily tracking poll. 
 
 ADVERTISEMENT 
 
 Obama, meanwhile, retained his 1-point advantage over Romney among registered voters in the survey, 48-47. 
 
 The survey is a rolling seven-day average through Oct. 24, so it completely encapsulates polling data since the second presidential debate last Tuesday night, Oct. 16, in Hempstead, N.Y., but includes only two days of reaction to Monday night’s foreign-policy debate in Boca Raton, Fla. 
 
 Gallup has received a lot of attention, as Romney’s lead among likely voters had been outsized in comparison to other polls. For most of the last week, Romney led Obama by between 5 and 7 points in the poll. 
 
 
 
 
 
 According to the RealClearPolitics average of national polls, Romney leads Obama by less than 1 percentage point, 47.7 to 47.1 
 
 
 
 
 
 An Associated Press-GfK poll released Thursday shows Romney edging Obama, 47-45. 
 
 But battleground polls show many states remain a toss-up. 
 
 In Ohio, a key state for both campaigns, a Time poll released Wednesday showed Obama up 5, with a 49-44 advantage, while a SurveyUSA poll showed the president topping Romney by 3. 
 
 A poll from conservative outlet Rasmussen put the two candidates tied in the Buckeye State, with 48 percent support apiece among likely voters. 
 
 The Gallup daily tracking poll has a margin of error of 2 percentage points.
– Mitt Romney's lead over President Obama stands at 3 points in today's Gallup tracking poll, and among registered voters Obama actually leads 48-47. The poll is noteworthy, the Hill explains, because Gallup has lately been much higher on Romney than all the other polls; he was ahead by 3 yesterday, too, but for most of last week, he was up between 5 and 7 points. The results back up a trend Nate Silver has been seeing: It appears Romney's rise has stalled. Yesterday he lost ground in five out of six daily polls. "This is the closest we've come in a week or so to one candidate clearly having 'won' the day … and it was Mr. Obama," Silver writes. "It's improbable that Mr. Romney would have a day like this if he still had momentum." Romney still has a slight edge in RealClearPolitics' polling average, but Silver's prediction model still has Obama as a 71% favorite to win.