[neverdem]

Is it possible that a huge number of the base didn’t want to vote for a Mormon?

It doesn't look that way.

The Case of the Missing White Voters

So who were these whites and why did they stay home? My first instinct was that they might be conservative evangelicals turned off by Romney’s Mormonism or moderate past. But the decline didn’t seem to be concentrated in Southern states with high evangelical populations.

IMHO, looking at the results of the House, a lot of working class whites didn't vote for the top of the ticket.

[paul544]

Doesn’t explain the Senate though...