Weekly Polling Report: The Convention Bump
by CA Pol Junkie
Polling over the summer is boring and not terribly meaningful, but we are almost upon the beginning of the fall campaign season. The first polling leaf to fall is the famous convention bump. Each party gets to rally around their candidate and get some free positive publicity. A few voters swing their votes accordingly. Historically, the size of the bump is all over the map, from essentially zero for Kerry to 14 points for Clinton. There may also be a short-lived veep bump, but this will blend in with the convention bumps this year since Obama and McCain are waiting until the last minute to announce their choices.
The big question on the eve of the convention is how big the bump will be for each candidate. To answer this question without the tedium of actually waiting to find out, we can look at crosstabs of the recent Bloomberg / L.A. Times poll. Although the poll shows Obama's support having slipped over summer, there is upside potential:
The poll found that McCain, long an unpopular figure among conservatives, has had more success than Obama in rallying his party's base. Nine out of 10 Republicans favor McCain, while just under 8 in 10 Democrats support Obama.
The prime goal of the convention will be to unify the Party. If the Democratic Party supports Obama at the same level as the GOP supports McCain, the increasing rate by which people align themselves with Democrats will put Obama in very strong position to win in November. Bringing the Democratic base up to the level of support in the GOP base will net Obama 3-4 points in the polls. It's hard to see that not happening, with Hillary Clinton, Al Gore, and many others rallying the base and reminding everyone of the important differences between the candidates. Obama also has additional upside potential because independent voters don't know him as well as they think they know McCain.
My prediction (worth at least as much as you paid for it) is that Obama will get an 8 point bump while McCain will get just two of those points back from the GOP convention. McCain is more a known quantity, he's not very exciting, and few people will be watching because Republicans are especially unpopular right now. That will leave Obama about 8 points ahead and in good shape a week after Labor Day.
The poll averages used are from pollster.com. A 10 point lead puts a state in the base for each candidate, which means it's not going to be the state to put one candidate or the other over 270. Since those states are boring, their status is not updated here.
The current pollster.com prediction would be Obama 317, McCain 221 with Ohio as the state that puts Obama over the top and Nevada as the closest state. There were shifts in both directions this week. Mississippi moved into McCain's base, while Arizona tightened into the competitive zone. McCain gained in Pennsylvania, New Hampshire, and Indiana, but Obama gained in Michigan and Nevada crossed over to the blue side of the divide. We'll see the beginning of Obama's convention bump in next week's polling report. I expect the largest gains to be in areas where Clinton did well in the primaries as her voters come home.
Obama Base (190 EV): California, Washington, Hawaii, Wisconsin, Illinois, DC, Maryland, New Jersey, New York, Connecticut, Rhode Island, Massachusetts, Vermont, Maine
Rasmussen 8/20 (7/24):
Obama 48 (49)
McCain 44 (43)
Minnesota (Obama +7.5) 208 EV
Survey USA 8/13-14 (6/13-16):
Obama 47 (47)
McCain 45 (46)
Pennsylvania (Obama +7.3) 229 EV
Selzer 8/18-20 (12/10-12/2007):
Obama 46 (49)
McCain 39 (41)
American Research Group 8/18-20 (7/19-21):
Obama 46 (47)
McCain 45 (45)
Research 2000 8/18-20 (11/16-19/07)
Obama 44 (46)
McCain 43 (43)
Florida (McCain +1.3) 221 EV
Rasumssen 8/18 (7/22)
McCain 48 (47)
Obama 46 (49)
American Research Group 8/18-20 (7/19-21)
McCain 47 (47)
Obama 46 (45)
Civitas 8/14-17 (7/14-16)
McCain 46 (43)
Obama 40 (40)
Georgia (McCain +6.0) 154 EV
Rasmussen 8/14 (7/17)
McCain 53 (53)
Obama 44 (42)
McCain Base (78 EV): Utah, Idaho, Wyoming, Nebraska, Kansas, Oklahoma, Louisiana, Alabama, Tennessee, Kentucky, West Virginia, Mississippi