It doesn't work that way.
There are people who don't think of themselves as political. They get up and vote when someone shows up supporting their one or two big issues. Such people are usually deeply moral a-political Christians. Such people very often vote for Republicans. Republicans are more likely to say something that motivates them. When a liberal Republican comes along, it's not that they pout and sit on their hands, they simply haven't heard anyone say anything that will drive them to the polls.
Not all voters are political hacks like us, thinking in terms of long-term strategy. They see the world in a much more cut and dry way. Too bad, but that's the way it is.
I've seen and heard this hundreds of times in dozens of focus groups over the years.
Oh no? Ask Bush 41 if it doesn't, in terms of the conservative vote. Ask Bush 43 if it didn't almost work that way when the Evangelicals sat on their hands in 2000.
It most certainly does work that way. Having one's base not show up because one isn't sufficiently hardcore happens in every election cycle.