In a post over at Townhall last week, I explored the striking gap between national public opinion trends and polling results in individual contested races. The former data set looks highly promising for Republicans — Allahpundit wrote about the generic ballot on Friday — while the latter offers little indication of a coming red wave. Why aren’t GOP candidates surging across the board in the midst of such an auspicious overall electoral environment? Why is President Obama’s toxic brand dragging down certain Democrats, but not others? When I posed these questions to Real Clear Politics’ top elections guru, Sean Trende, his answer boiled down to, just wait awhile:

“These [2014] Senate races are just now really beginning to engage, and undecided voters are starting to get a look at the Republican candidates,” Trende explains. “That doesn’t mean they’re going to like what they see in every case, but the fact that you still have about 15 percent of the electorate undecided in a place like Iowa suggests that we will eventually see a clear break for one candidate or the other. It’s possible that [undecided voters] will break evenly, but I wouldn’t bet the farm on that.” For an explicit data point on how undecideds might ‘break,’ Trende mentions a recent Arkansas survey conducted by Democratic pollster PPP: “They polled undecided voters and found that Obama’s job approval rating among that group, in that state, is 13 percent. So we’d expect those people to break disproportionately toward [Republican challenger Tom] Cotton.” … Trende raises presidential approval ratings as an instructive factor: “Most of these vulnerable Senate Democrats’ vote shares [in polling] roughly correlate to the president’s job approval rating. So you have this mass of undecided voters who don’t think much of the president, but haven’t decided to vote for a Republican. In states like Louisiana or Alaska, the most reasonable expectation is that a lot of those people eventually move toward Republican candidates,” he says, adding that the same pattern could hold true in those purple state races, but with a less dramatic split.

This explanation is entirely plausible. The electorate is deeply dissatisfied with the president and the nation’s trajectory, so it would follow that those political winds will start to batter Democrats as voters “tune in” to the midterms. Democrats benefited from a similar confluence of events in 2006. The country was unhappy, Republicans were playing defense on major domestic (Katrina) and international (Iraq violence) issues, while President Bush’s job approval hovered in the high-30’s to mid-40’s range — with majorities disapproving. (Sound familiar?) When the smoke cleared on election night, Democrats had netted six Senate seats, 31 House seats and six governorships. Flash forward to 2014, and major Republican gains in House and governor elections are unlikely because the party is already approaching its historical ceiling on both fronts, sitting at 233 and 29, respectively. If this cycle goes well, those numbers might get a slight bump (say, 240 and 30), but most of the “low-hanging fruit” was plucked four years ago. The real action is on the much-discussed Senate side, where a wave year could yield a bumper crop of pick-ups for the GOP. On paper, if things broke reasonably well for Republicans, they could realistically net between nine and 11 seats…and that bullish projection excludes reaches in states like Minnesota and Oregon. In his post linked above, AP said he fully expects the GOP to at least secure narrow control of the upper chamber: “Even I’m confident that they’re going to retake the Senate. The question is the margin, not who’ll control the chamber.”

Rare confidence from Hot Air’s resident Eeyore. But is it well-grounded? In the words of Lee Corso, not so fast, my friends. Over the weekend, Bill Clinton stated that Democrats have a “better than even” shot at retaining the Senate. That might be a slight exaggeration, but I don’t think 42 is necessarily too far off. Consider the math: If Republicans, as expected, successfully defend every seat that is currently red (the most vulnerable being Kentucky, Georgia, and, um, Kansas), they’ll need to win six Democrat-controlled seats in November. Open races in Montana, South Dakota and West Virginia look like locks at this stage. Three more. Endangered Democratic incumbents appear to be in real trouble in Alaska, Arkansas and Louisiana — each of which was carried comfortably by Romney/Ryan in 2012 — but none of their challengers have put them away. All three races remain too close to call. Continuing with our hypothetical scenario, let’s say the GOP eventually wins two of those three contests (the likely Louisiana runoff could keep things in limbo for several weeks). They’d still need at least one more victory to oust Harry Reid as majority leader. Where would that win come from? Possibilities abound, but none of them look like layups. By all accounts, Kay Hagan in North Carolina should be a sitting duck, but Democrats are spending prodigiously to protect her, and she’s ahead in every recent poll. In Iowa, the race remains deadlocked, and a deluge of lefty spending is keeping deeply flawed Democratic nominee Bruce Braley very much alive. In Colorado, Cory Gardner is running a virtually flawless campaign against an incumbent who’s voted with a very unpopular president 99 percent of the time, yet he’s still trailing in most polls by a handful of points. In New Hampshire, Scott Brown is comprehensively out-working Jeanne Shaheen, who’s clearly hoping to ride this thing out by relying on attack ads, a la Hagan and Udall. Brown received some welcome polling news this morning (here’s another), but the conventional wisdom continues to hold that this seat remains in the ‘leans Democrat’ column. And in Michigan, in spite of the occasional positive survey result, Terri Lynn Land lags behind Democrat Gary Peters by a not-insignificant margin in most polling.

If 2014 witnesses even a modest GOP wave, you’d expect at least one or two of those statistically-tied races to fall into the Republican column, thus securing a new majority. But as we wait for Trende’s late-breaking undecideds to make their move, the possibility of Democrats’ firewall holding cannot be ruled out. In spite of these numbers. And these. I’ve been telling audiences for weeks that I wouldn’t be especially surprised to see a Republican gain of five seats on election night, with December’s Louisiana runoff deciding the Senate’s fate. I’m now manning up and putting that semi-prediction in writing. My relative pessimism is driven by the fact that whenever a “Republican wave”-looking poll emerges (Scott Brown has tied Shaheen! Tom Foley is ahead by six in Connecticut’s gubernatorial race!), countervailing numbers spring up (Hagan by four, though she’s stuck at 45. Gov. Pat Quinn erasing a consistent deficit and grabbing an eleven-point lead in Illinois, at least in one poll. Gov. Nathan Deal struggling against Jimmy Carter’s grandson in Georgia, etc). I have the utmost respect for Sean Trende’s analysis, and he certainly has history on his side as he projects a seven or eight-seat Senate gain for Republicans. But until the data starts to reflect the expected rightward cascade of undecided voters, Republicans rely on that expectation at their peril. Having killed your buzz like a pro, I’ll at least have the decency to leave you with this:

Make it happen, people.

UPDATE – Case in point. While Bush’s unpopularity was death on Republicans, many Democrats are substantially out-performing Obama: