Trailhead: A campaign blog.

Worthless Exit Polling in Mass. and Mo.

Exit polling conducted in Massachusetts and Missouri appears to have drastically overestimated Barack Obama’s performance, placing him within several percentage points of Hillary Clinton. With more than 50 percent of precincts reporting in Massachusetts and 32 percent in Missouri, Obama trails Clinton by more than 15 points in both states.

CNN.com makes it a little difficult to deduce this about the exit polls on first glance, because they do not carry out the basic multiplication to determine the final results. (One can’t help but suspect they’re a little embarrassed.) But they do break out how many women turned out versus men, and how the genders split between the candidates.

For the Massachusetts exit poll, a little third-grade math tells us that:

Clinton: (58% of voters were female) * 57% of women voted for Clinton + (42% of voters were male) * 42% of men voted for Clinton = 51 percent of the vote

Obama: (58% female) * 40% of women for Obama + (42% male) * 54% of men for Obama = 48 percent of the vote

Back here in reality, Clinton leads Obama in Massachusetts by 15 points with 59 percent of the electorate reporting.

In Missouri, the same exit poll calculus gives us Clinton with 47 percent to Obama’s 45 percent. With close to half of precincts reporting, Clinton leads Obama by 14 points.

With that kind of batting average, perhaps we should avoid any sweeping conclusions from all the other numbers in the exit polls. Or, better yet, ignore them altogether.

Note: These exit poll numbers are changing constantly, so the links won't reflect the exact figures in this post. We'll keep an eye on them.