It can be done a number of ways as you outline, but the only way to win in 2016 is convince about 3 million people that voted for Obama in 2012 (and probably in 2008 as well) to vote for the Republican candidate.
It can’t be done by squeezing out 6 million more “true conservatives” to turn out that didn’t vote in 2012 because
1) they don’t exist
and
2) If they did, the vast majority are in states that Romney won easily anyway.
When the country is in trouble, people should support ideas that actually work. Sell that notion.