A fascinating article from the NYT’s FiveThirtyEight blog makes the case that the Republican Party has become dependent on the conservative block, which in turn is the reason it is difficult for GOP candidates to moderate, for fear of losing their voting base.

The essence of the post is exit poll data on the political ideology of those who voted for Republican candidates. The chart shows just how many GOP voters consider themselves conservative in elections since 1984.

Here’s what the chart will show: The Republican Party is dependent, to an extent unprecedented in recent political history, on a single ideological group. That group, of course, is conservatives. It isn’t a bad thing to be in favor with conservatives: by some definitions they make up about 40 percent of voters. But the terms ‘Republican’ and ‘conservative’ are growing closer and closer to being synonyms; fewer and fewer nonconservatives vote Republican, and fewer and fewer Republican voters are not conservative.

And here is the magical chart:

GOP voting

The jump in conservative voters and the decline in moderate voters since 2000 makes for an interesting analytic. Are more people becoming conservative or are more conservatives voting Republican? Where are moderates going?