Some conservatives have decided that it is time to punish Republicans for abandoning their roots. McCain happens to be at hand. (Gratitude to Classical Values for this.)
I can understand this somewhat. Reliable conservative NH Senator Judd Gregg has been softening in a Washington direction slightly, and I have thought it would be good to "send him a message." But there are difficulties with this type of gamesmanship politics, and conservatives should be properly cautious before embracing it.
Caution #1. There might be some general agreement on what is the conservative position on most issues, but there is not a general consensus as to what ranking order those issues come in. When one starts to insist what a Real Conservative is, it nearly always involves insisting not only on your position, but your ranking of which issues are most important. You can easily find other conservatives who will rank the issues differently, and all your exhaling violently about ignoring the Constitution or creeping socialism doesn't change that. You and your best buddies do not get to define True Conservatism.
Caution #2. The purpose of elections is not for you to feel represented by someone you approve of, but for the country to be governed. Wanting to feel heard is what led the antiwar crowd to circulate Not In Our Name petitions. It is Democrats who vote on the basis of "cares about people like me." Your positions may be as conservative as Coolidge, but you're thinking like a fuzzy liberal when you do this.