The obvious answer is no, he would have lost without their support. But the point I am making is that there were a number of distinct groupings -- all of whom contributed. To pick one and say -- it is because of them -- does not follow. Reason is you could make exactly the same argument about any of the other distinct groups and say -- if they had stayed away, he would not have been elected.
Thus -- to make the statement that he wouldn't have been returned to the White House without the support "of a certain percentage of Evangelical Christians who believe in the inevitability of the imminent Second Coming, and the Battle of Armageddon" is a true statement -- but not really a meaningful one.