You can just ask Mitt Romney why that's so important.
In the 2012 presidential race, the margin of Romney's final defeat can be traced in part to a traditional Republican-leaning base of voters not turning out to vote in sufficient numbers, namely Christian evangelicals. Indeed, millions of Christian evangelicals have been estimated to have sat out the past two elections, with Republicans losing both contests.
For Trump to produce a different result, turning out the Christian evangelical voters in the battleground states is crucial, something his campaign team has clearly recognized by hiring numerous operatives in key states who are focused on outreach to, and "get out the vote" efforts targeted at, Christian evangelicals.
You only need to look at how tight some of the races were four years ago to see how the stakes are in the battleground states -- and what a difference turning out Christian evangelicals could make.
For example, in Florida (29 electoral votes), with over 8.3 million votes cast, President Barack Obama's margin was 73,189 votes
. Meanwhile, Virginia (13 electoral votes) was carried by Obama by a margin of 115,910 votes
out of over 4 million cast. Ohio (18 electoral votes) had about 5.5 million votes cast, but Obama won by a margin of 103,481
. Finally, New Hampshire (4 electoral votes) was won by Obama by a margin of 40,659
out of over 700,000 votes cast. That means that if the Romney campaign had secured only 350,000 more votes across these four states, Romney could have eked out a 270 to 268 win in the electoral college.
The importance of turnout could not be clearer, a fact clearly recognized by some groups who are already focused on helping to increase the numbers of Christian evangelicals who head to the polls in November. Franklin Graham has been traveling the country and hosting large prayer rallies in state capitals, as part of a 50-state "Decision America" tour, since the first of the year. Another group, My Faith Votes, is being led by Honorary Chairman Ben Carson.
Meanwhile, Lift the Vote is pursuing a more "hands on, high touch" approach. Lift the Vote has three colorfully decorated buses focused on three different regions of the country (North Carolina, Florida, Virginia; Ohio, Pennsylvania, Michigan; and Arizona, Colorado, New Mexico, Nevada) urging Christian evangelicals to pray and proclaim: "I'm a Christian. I'm voting!"
"Our votes are our voice. All the talk and opinions mean nothing if we don't vote," Dana Hunsinger Gill, co-chair of Lift the Vote, told me. "When Christians don't vote we silence what we know and our voices, allowing others to choose our leaders, the direction of our nation, and the critical policies that affect us and our families. From the Supreme Court to the protection of religious liberties for all, to issues that directly impact the moral decline that we have been experiencing for too long, it has never been more important in my lifetime for followers of Jesus to be organized, pray together, and vote."
The Lift the Vote bus tours include appearances at large sporting events, festivals, Christian concerts, church services and other community gatherings in the targeted states. Activists are distributing stickers declaring "I'm A Christian. I'm Voting!" as part of the Lift the Vote outreach. "Voters in Iraq in 2005 dipped their fingers in purple ink as they cast their first votes and images of those upheld fingers became a symbol of their pride in participating in a free election process," Gill told me. "They risked their lives to cast their votes. We encourage Christian voters to draw a small red cross on their forefinger and proudly display it as a demonstration and reminder of our commitment to choose our leaders by voting in this election."
Evangelical Christians are not, of course, the only faith-minded voters that could hold the key in very tight races. That's why, for example, last December the U.S. Council of Muslim Organizations -- composed of members including the Council on American-Islamic Relations (CAIR), the Muslim Legal Fund of America, The Mosque Foundation, the American Muslim Alliance and others -- announced plans to register 1 million Muslims to vote in the 2016 US elections. The group also announced plans for a nationwide bus tour to promote voter turnout in Muslim communities. CAIR is, for its part, specifically targeting key battleground states like Florida, Ohio, Virginia and others to engage and mobilize their voters.
All this suggests that the campaigns can take nothing for granted on Election Day -- concerted get-out-the-vote efforts among key constituencies could tip the scales in very different ways from 2012. But whatever happens on November 8, one thing is clear -- the winner of this year's election will have not only convinced voters to support them, but also have managed to get them to turn out in greater numbers than those of his or her opponent.