I spent a few days last week attending a professional conference in Denver. I had never been there before and the area is quite beautiful. Just before heading back on the plane, I took a short daytrip to the surrounding Rocky Mountain area, which was quite spectacular.

While one major difference between the New York area and the Denver area is the climate (morning temperatures, at least during my stay, were usually in the 30s) and topography, there are sharp political differences as well.

Unlike the situation in New York, Colorado is a very closely contested state (albeit with a slight Republican tilt) and it is in the midst of numerous tight campaigns. One particularly high profile race in Colorado's Seventh Congressional district, which largely encompasses the Denver suburbs. The most recent poll had the race exactly even.

Of course, the close races produced numerous campaign commercials, more often than not negative in tone. Almost inevitably, they featured a grainy and unflattering black and white picture of the opponent accompanied by ominous music.

All of this exposure to commercials led to a few thoughts about campaign advertising and in particular the role of negative advertising.

I have to say that many negative ads, including commercials on behalf of candidates who I may be inclined to support, make me less rather than more enthusiastic for the sponsor. With few exceptions, I particularly don't like the "gotcha" advertising that dredges up personal or financial issues relating to the opposing candidate that are unconnected to the major issues of the campaign.

This not to say that there is negative advertising is inherently wrong. It is important that voters treat the candidates critically and understand possible downside of the nominee's stands on the issues. To use a fairly typical example, a candidate promising more spending or tax cuts can fairly be criticized if he or she fails to offer any ideas as to funding these programs. And Democrats have every right to connect Republican candidates with President Bush if they feel that works to their advantage.

Moreover, in some cases it is not unfair to attack candidates for bad things they have done. For example, based on this week's report of the state Ethics Commission, it is certainly appropriate to criticize Comptroller Alan Hevesi for the use of a state driver to chauffeur his wife for years. And there may be enough suspicious activity surrounding New Jersey Senator Bob Menendez to warrant ads raising ethical issues.

On the other hand, there are examples where attacks go beyond the pale. One striking example is in the close Senate race in Tennessee this year between Democrat Harold Ford and Republican Bob Corker. In an ad actually disavowed by Mr. Corker, Mr. Ford, who is in his 30's and single, is attacked for attending a Playboy Magazine party in connection with a Superbowl that he attended. (A blonde model in a provocative outfit says in the ad, "I met Harold at the Playboy party.") My honest reaction is that if this is the worst thing that Mr. Ford has ever done, he must be a pretty clean candidate.

Certainly advertisements, including negative spots, are part of the political landscape. But candidates, no less than voters, should tread with care.