Ted Cruz doesn’t have any way of reaching independent and persuadable Democratic voters. It’s important to point out that part of Cruz’s unpopularity is his ideological conservatism. Successful national Republicans usually have a few “heresies” to advert to the center. The Bushes portrayed themselves as compassionate conservatives and triangulated on issues like education. McCain made himself a scourge of the corruption of money in politics, even when it brought him into conflict with typical conservative views on free speech. Romney was a businessman and technocrat, not merely a creature of politics. By contrast, Cruz is a man who seems to have received his entire political formation within the ideological hothouse of the conservative movement.
Cruz’s “disagreements” with the party at large tend to be about tactics. He’s for the extreme ones. Or they are hedges between different competing schools of thought within conservatism. He is willing to split the difference between neoconservative interventionists and conservative Jacksonians on issues of foreign policy. But this never, ever dulls the sharp edges of his partisanship.
Conservatives should be wary of having Cruz as their candidate precisely because he offers such a high-octane distillation of their views. As it would be for any movement promoting its ideas at their rawest state, an up or down vote for “conservatism” is a losing one for Republicans. That’s why the party historically tries not to nominate people like Ted Cruz.