Yeah, yeah, the poll was commissioned by Kos, but we’ve been over this before. Their pollster’s reputable, and if they were gaming the numbers here, some of their results would have tilted the other way. Hayworth beats all four hypothetical Democratic challengers? Obama’s net approval rating stands at -14? A plurality prefers a candidate who favors repealing ObamaCare to one who supports the law (44/39)? Not very Kos-y.

Despite the conventional wisdom that McCain could be vulnerable to an intra-party challenge, we find that McCain has a fairly solid level of favorability among Republicans. His current favorability among GOP voters stands at 76%, with only 19% expressing disapproval.

Hayworth, meanwhile, may well have some upside in the GOP primary, as he is still unknown to about a quarter of the electorate. And it is worth noting that among Republicans, he is well liked (a 61/16 favorability spread).

However, his upside might be limited to a GOP primary. In a general election, he is clearly a greater liability for the GOP. Hayworth is much less popular among both Democratic and Independent voters, and sports an net negative favorability (34/42) among all voters, joining only President Obama (41/55) and incumbent GOP Governor Jan Brewer (39/54) in minus territory.

McCain’s favorable rating stands at just 47/46 but it’s the grassroots’ misfortune, I guess, to be saddled with a “true conservative” champion who’s even less popular than he is. Incidentally, this is a poll of likely voters — just as Rasmussen’s polls are, of course. Except that when Rasmussen polled this same race two weeks ago, they found McCain’s lead to be just seven points. I don’t get it. What could have happened between now and then to rescue McCain’s sagging campaign and reinflate his lead?

Oh, right. That. More from Rasmussen’s mid-March analysis:

The latest Rasmussen Reports telephone survey of likely Arizona GOP Primary voters shows McCain ahead 48% to 41%. Three percent (3%) favor another candidate, and eight percent (8%) are undecided.

Following the announcement that Sarah Palin would campaign for his reelection, McCain opened up a 53% to 31% lead over Hayworth in January. The two men were in a near tie in November.

Every time Palin enters the equation, Maverick gets a jumbo-sized boost. Which is great news for her — proof positive that she’s an influence on conservative voters — but not so great for McCain-haters who are hoping for a Hayworth upset. If this race gets close near the end, you’d better believe ol’ Mav will be on the horn to Wasilla asking for another quick whistle-stop tour of Arizona. And there’s no reason at all to think Sarahcuda will say no, especially if given such a plum opportunity to play Senate kingmaker. Exit question: Blame Sarah?