The story so far:
John Sides said that Ted Cruz was hurting his chances at the nomination by alienating Republican Senators. Dave Hopkins said: maybe not. I then did a Salon column over the weekend more or less taking Dave's side.
But any nominee needs broader support in the party—support beyond his natural base. In fact, Cohen and colleagues show that it is support from party leaders outside a candidate’s base that is truly potent: it appears to drive fundraising, media coverage, and ultimately poll numbers.[...] My point is that the kinds of behavior that would earn him the endorsements from Senators who are not his conservative kindred are likely to earn him the support of other party leaders who aren’t in the Senate and are outside his natural base. (And, by the way, that’s a base he can’t even count on if Paul runs.) And the support of these other leaders is what would be most valuable. That’s why I think Cruz’s M.O. isn’t optimal. He’s antagonizing some of the same people that would be most useful to have in his corner.And Dave took the bait and responded in detail in the comments. He argues that personal relationships are perhaps less important than other factors in winning endorsements. And he also argues, as I did in the Salon piece, that the kinds of "go along to get along" behavior that winds friends within Congress has rarely helped much on the campaign trail.
John then responded to Dave (we're still in comments over at the Monkey Cage), saying "I’d suggest that Cruz, by engendering resentment among at least some of his colleagues (and others like them outside of the Senate), may have a harder time convincing enough Republicans" to support him.
I'd say the parenthetical is doing a lot of work there -- the "others like them outside of the Senate" bit.
What I think, I suppose, is that outsiders -- that is, party actors outside of Congress, and especially outside of Washington -- probably heavily discount either positive or negative reputation for "plays well with others" that's based primarily on intra-Senate testimony. They will look for cues about ideology, sure. But the rest...I'm just not sure that outsiders consider Members of Congress a reliable source of information. Or at least: Washingtonians tend to overrate the extent to which intra-Senate reputation for collegiality will wind up mattering.
In other words, what matters here is whether party actors outside of Congress think of themselves as "others like them" or not; that is, whether they think of themselves and the Senators upset by Cruz as part of the same set of non-crazy Republicans, or if they instead them of those Senators as "Congress" and themselves as "not-Congress." And I think there's some evidence, over the years, that it's the latter.
On the other hand...there's a lot more of the national Democratic and Republican national parties than there was in 1960, or even in 1980. That might matter, and it might tend to make John's point relatively stronger -- depending, that is, on whether the rest of the national party things of Congress as a body apart or not.
What's really at question here is about the various different components of our expanded parties, and how they fit together. Clearly Republican Senators are a part of the larger Republican national party network, and each Senator is part of his or her state's party network, but exactly how important they are to the presidential nomination process, either directly or through their effect on reputation, is a lot trickier to figure out.
And I agree with John that we're talking tendencies here, not absolutes. Indeed, on balance I agree with him (and I suspect that Dave does to, although of course I can't speak for him) that "Cruz’s behavior, if it continues, is doing more to decrease his chance of winning the GOP nomination than to increase it." I just think it's probably a minor factor, and one that may be in part balanced out by the upside of using the aggressive strategy. But, yes, I think that if Cruz could build his reputation as a demagogue without actually annoying his fellow Senators, that would likely be a bit better for his presidential prospects.