As most of us have observed this week, the Republican presidential contest is starting to get negative - although some candidates seem to be avoiding one another. This is from the New York Sun:

As the Republican presidential race devolves into a five-man free-for-all of sustained attacks and sharp rejoinders, one pair of candidates, Mayor Giuliani and Michael Huckabee, has avoided direct conflict, exchanging more compliments than criticism.

Mr. Huckabee, who has leapt to second in the Iowa polls, has drawn increasing fire from GOP contenders Mitt Romney and Fred Thompson, but not from Mr. Giuliani, who has described him as "wonderful."

The former Arkansas governor seemed to respond in kind yesterday when he took Mr. Giuliani's side in the former New York mayor's bitter fight with Mr. Romney over their respective records as a mayor and governor.

"I think Mitt was the one who went after Rudy more than Rudy went after Mitt," Mr. Huckabee told reporters in a conference call, when asked for his thoughts on the dispute that has played out in New Hampshire in recent days. Messrs. Romney and Giuliani have taken harsh shots at each other on a range of issues, including spending, taxes, immigration, and executive appointments.

Meanwhile, nobody thinks enough of John McCain to attack him. This is from the Politico:

'The only thing worse than being talked about is not being talked about," Oscar Wilde once said, and that is the problem the John McCain campaign is now grappling with.

Over the past few days, Mitt Romney has been attacking Rudy Giuliani (and vice versa), and Fred Thompson has been attacking Mike Huckabee (and vice versa), but who has been attacking McCain?

None of this is surprising. In fact - these candidates are doing what presidential candidates usually do.

First, note that these attacks are not coming through paid media. Instead, they are coming through the press. What happens is that one campaign puts out a negative press release, or makes itself available for questions so that it can slap another candidate around. The press reports the "story" - and presto! A free negative advertisement. Not only are they free of charge, they also carry with them real benefits. Scholars who have looked at these types of attacks have speculated that voters take them more seriously than negative ads because the attacks are packaged as news. Furthermore, the fact that they are on the news might inoculate the attacker from the blow back that can come from going negative.

Second, note the timing. I have written before about how pundits wrongly think it is a good idea to launch negative attacks months and months before an election. It is not. Usually, candidates save this kind of attack for when (a) there is a delegate rich state having an election soon, or (b) there is a "high stakes" event coming soon. These particular attacks are happening in advance of Iowa and New Hampshire - the events with the highest stakes.

Third, note the directions of the attacks. We have Thompson and Romney attacking Huckabee. We have Romney attacking Giuliani, and vice-versa. We have Giuliani and Huckabee explicitly laying off each other. We have nobody attacking McCain, but McCain is going after Giuliani and Romney. What explains this pattern - especially the strange détente between Giuliani and Huckabee? Some have suggested that it is because Giuliani and Huckabee are appealing to different voters. There is thus no reason for them to attack one another. Others have suggested that Giuliani and Huckabee do not see each other as electoral competitors. Giuliani is weak where Huckabee is strong, and vice-versa.

These explanations are not mutually exclusive - they may even be causally related to one another, and I would not be surprised if both were motivating the two campaigns. Both speak to the idea that the primary campaign is a war of attrition in which each candidate's goal is to eliminate his opponents. However, the research that I have seen indicates that ideological proximity does not explain why candidates attack through the media. Instead - it has to do with where they are in the polls. Researchers have found a few basic features of mediated attacks:

(a) Frontrunners tend to avoid negative attacks, except when (i) they are attacked by somebody, or (ii) a challenger is on the rise and is now threatening their position.

(b) Challengers attack frontrunners (or those who are ahead of them in the polls).

(c) Challengers are more likely to attack when given the opportunity (e.g. debates); frontrunners are neither more nor less likely.

With these generalities in mind, the direction of the attacks starts to make a lot of sense. Giuliani and Romney see each other as electoral threats, presumably because both of them want to do well in New Hampshire. In particular, the fact that Romney persists in attacking Giuliani may be a sign that the former expects the latter to close the gap. This is also why McCain is attacking Romney and Giuliani - they are in front of him in the Granite State. The fact that Huckabee is on the rise in Iowa is what has precipitated the attacks on him from Thompson and Romney. They see him as a threat in the Hawkeye State.

Meanwhile, the fact that Giuliani is not attacking Huckabee is an indication that Giuliani does not mind finishing behind Huckabee - so long as Huckabee damages Romney. Giuliani would probably not mind finishing third in Iowa if it means that Romney finishes second, or barely finishes first. Relatedly, the fact that Huckabee has remained mum on Giuliani - who is strong in New Hampshire - indicates that Huckabee is not making a significant play for votes in the Granite State. In fact, Huckabee might intend to write off New Hampshire all together - and take a victory in Iowa down to South Carolina. At that point, we could expect Giuliani and Huckabee to go after one another.

Finally, the fact that nobody is attacking John McCain is a sign that nobody sees him as an electoral threat. While it is true that he is close behind Giuliani in the RCP average of New Hampshire, his trend line has been flat for five months. It may be the case that Giuliani and Romney expect him to fade as both increase their television advertisements beyond what the cash-strapped McCain campaign can do. If this is what Rudy and Mitt anticipate, there is no reason to slap McCain around.

Now - none of these are earth-shattering conclusions. Many people (myself included) have drawn similar inferences about the state of the Republican race independent of these negative attacks. However - because we know some general trends about negative attacks (i.e. who generally attacks whom, when do they generally attack, etc) - we can draw some inferences about how these candidates view the race. This is of great value because it can confirm or disconfirm our initial impressions. Candidates are the true experts on the horse race. And, insofar as we can infer what they think about the campaign, we can understand the race better.

As this campaign unfolds - and especially as the general election begins in earnest - you will see that this is a common analytical strategy of mine. Drawing inferences about candidate perceptions based upon candidate actions is possible if you know enough about how campaigns work. And, if you read candidates correctly, you can tease out some real insights.

So - I would suggest that, while tonight's Republican debate probably will not change many minds (and therefore cannot really be discussed in terms of winners and losers), it will offer us further confirmation on who views whom as a threat, and therefore who is really competing where. So, don't worry about who is winning the debate. Don't play the same meaningless game the press plays. Instead, watch to see how the five top candidates go after one another. Who attacks whom? What are the lines of attack? Do they wait until they are attacked by somebody else, until they are prompted by the moderators, or do they just go for it without provocation?