Trailhead

The Lake Effect

Warning: The post you’re about to read is very math-heavy, and very speculative. But it’s worth a read if you’re waiting on the returns from Lake County in Indiana, which may not come in until after midnight.

Lake County is the only substantial county yet to report its vote tallies. We crunched some numbers to estimate what percentage of the county’s vote Obama would need to earn to beat Clinton overall in Indiana.  

First, we have to project how many people have voted tonight in Lake County based on Indiana’s overall turnout. To help, we’ll compare those numbers to the general election turnout in 2004.

Tonight, 1,039,781 people voted with 84 percent of precincts reporting. If you extrapolate it out to 100 percent, about 1,237,835 people will vote overall in the Democratic primary.  

In 2004, 2,445,153 people voted for president in Indiana, 967,346 of them for Kerry. Tonight’s estimated turnout is almost exactly half of the total votes cast in ‘04.

Now, we’ll zoom in on Lake County, and using its contribution to the overall vote in 2004, we’ll estimate the county’s turnout in today’s primary.  

In 2004, 108,219 Lake County residents voted for John Kerry, while 68,512 voted for Bush. Combined, that’s 176,731. That’s 7.2 percent of the state’s total vote, 11.2 percent of the state’s total Democratic vote.

Now, we’re at a crossroad in our assumptions. We’ll set up a range for Lake County’s possible turnout. Our lower bound will be that Lake County makes up 7.2 percent of the state’s total vote in the primary. Our upper bound will be the 11.2 percent figure.  

Multiplying our bounds by the total projected turnout for today’s primary vote, we can get hard numbers for our projected turnout in the county.

If Lake County comprises 7.2 percent of the state’s total primary vote, it will cast 88,442 total votes. If it comprises 11.2 percent of the state’s total primary vote, it will cast 137,006 votes.

Obama currently trails by 42,500 votes with 84 percent reporting.

Now, we’ll calculate the percentage of votes Obama needs to win in Lake County, using both of our bounds.

If the county casts 88,442 votes (7.2 percent of the state’s total), he’ll need to win 74 percent of the votes in the county —65,471 total—to get the net gain of 42,500 he needs.  

If Lake County casts 137,006 votes (11.2 percent of the state’s total), he’ll need to win 65.5 percent of the votes in the county —89,739 total—to get the net gain of 42,500 he needs.

As you can see, Lake County’s turnout greatly affects the percentage of vote Obama needs from the county to overtake Clinton. Both numbers are achievable, though, because Lake County includes Gary, Ind., which is 85 percent African-American.