In 2008, Obama’s candidacy drove historic black turnout and support for Democrats, contributing nearly half of Obama’s margin of victory.  Four years later, the GOP has nominated the first Mormon nominee for the Presidency, and some argue that Mitt Romney’s background might help his chances. While the effect of prejudice is difficult to judge, it is possible to gauge potential gains. And unfortunately for the Romney campaign, increases in Mormon turnout and support for Romney are only likely to help at the margins in a limited number of swing states.

Although Mormonism is among the fastest growing religions in the country, it remains one of the smallest in the United States, making up just 1.7 percent of the population. At such a small size, their impact on the election would be negligible were they distributed evenly across the country. However, 76 percent of Mormons are concentrated in the West, allowing them to play an outsized role in several states. Mormons make up the largest share of the population in Utah and eastern Idaho, where Mormons constitute more than half of all residents. Outside of those two states, Mormons exceed 25 percent of the population in just a handful of rural counties. As a result, Mormons only exceed 5 percent of the population in two other states: Nevada and Arizona.

Although both states are potentially competitive, neither Obama nor Romney have aired advertisements in Arizona, which leaves Nevada as the only true battleground state where Mormons constitute more than 5 percent of the population, at just 6.5 percent. Mormons make up just 2.8 percent of the population in Colorado, the next battleground state on the list. After Colorado, Virginia comes in third with a Mormon population representing just 1.1 percent of residents.

Nevada’s Mormon population is large compared to most states, but that does not make it especially significant. For comparison, African Americans constitute 5.9 percent of residents in Kansas, and I don’t recall reading too many articles devoted to the boost Obama might get from a big black turnout in Topeka. In fact, there are more African Americans (8.1 percent) than Mormons in Nevada. We can go on: Hispanics make up 6.4 percent of residents in Arkansas. The takeaway: While Nevada is one of the most Mormon states, its Mormon population just is not very large.

Increased support and turnout among Mormons can help boost Romney in Nevada, but not by much. In addition to not constituting a large share of the population, Mormons already offer overwhelming support to Republican candidates. Gallup’s September and October polling from 2008 showed McCain leading Obama among Mormons by a wide 75-19 percent margin. Similarly, the Utah exit poll showed that McCain won the Mormon vote 78-19. How much more could Romney gain? According to Gallup, Romney leads 84-13 among registered Mormon voters, suggesting modest but not shocking gains. Secondly, Mormons are generally understood as a high turnout group, which reduces the extent that Romney can make added gains by registering or turning out new voters, as Obama did with African Americans in 2008. It should be noted that I cannot find any strong evidence to support the conventional wisdom about Mormon turnout, except that Mormons made up 75 percent of the Utah electorate, even though they constitute just 61 percent of the population.

What can Romney squeeze out of the Mormon vote? Here's a hypothetical. Suppose that Mormon turnout increases by as much as African American turnout increased in 2008 and Romney receives 87 percent of the Mormon vote—giving him the entire undecided Mormon vote in Gallup’s poll. What would that yield in Nevada? 15,000 votes. Different assumptions would yield a higher or lower numbers and there’s a margin of error involved here. 15,000 votes can matter at the margins, but it is hardly game changing, especially in a state that voted for Obama by 120,000 votes in 2008 and that Harry Reid won by 40,000 votes in 2010. Although one should generally be quite skeptical of claims that a Mormon candidate would deflate evangelical turnout, even the slightest countervailing forces could reverse Romney’s gains.

Single demographic groups rarely swing elections on their own, and Mormons are no exception. Romney’s faith will probably boost Mormon turnout and support, but it is unlikely to prove decisive in any state. Mormons make up a larger share of the population in Nevada than any other battleground, but, even in the Silver State, there just are not enough Mormons to swing anything other than the tightest race.

*Assumptions: The Mormon voting age population (VAP) in Nevada was estimated based on Utah’s VAP (67 percent VAP). Nevada Mormons were assumed to vote 78-19 for McCain in 2008, 87-13 for Romney in 2012. Nevada’s Mormon turnout was assumed to be 60 percent of VAP in 2008, 65 percent of VAP in 2012, which boosts the Mormon share of the electorate from 7.2 percent in 2008 to 7.9 percent in 2012. It should be emphasized that these figures are not authoritative.