A great number of things can affect turnout in an American election. The perceived importance of the positions on the ballot. The collective mood of the electorate. The competitiveness of the election. And, yes, the weather. Even rain can scare off some voters.
In Iraq today, the biggest factor will be whether you will die for voting.
Quite a sobering difference, isn't it?
"We want to have elections," one resident of Samarra said, "but we are afraid that anyone who votes will be killed."
It's a very real fear. Inside of one month, 120 Iraqi security troops and civilians were killed in Samarra, Tikrit and Baquba in the run-up to today's election. And that's during a period of intense U.S. troop activity in the region.
The head of Fallujah's election committee quit when insurgents threatened his wife and children. "Having elections in this province is impossible," he told The Boston Globe.
Well, the coalition is asking for the impossible to get done today - in the face of mortal fear.
Such a picture should make our reasons for not voting melt away into a turbid pool of shame.
The next time you're upset about having to wait in line to vote, or the next time you find the least little excuse not to bother, think of our Iraqi friends who risked their lives today to merely sip from the cup of freedom that overflows here.
Some 280,000 Iraqis living in 14 other countries also were welcome to weather all manner of hardship to vote - including traveling many miles to register, and a second time to vote - at 74 special polling places outside their native land.
Many Iraqis and coalition troops have made the ultimate sacrifice to make today's vote possible - just as many of 21st-century America's ancestors did.
For us not to vote when literally given the chance, when there is no reasonable fear of bodily harm, is to dishonor them all.