I'm looking for a new web host for my politically oriented site, but I'm worried that if someone gets upset at an editorial on my site, he may cost me money by continuously loading my homepage and exceeding my data transfer limit. Are web hosts able to prevent this?

You would probably have to have one or more of the following for that to be a concern:

1) Really low bandwidth quota
2) Really big web page
3) Really determined person
4) Somebody with a lot of bandwidth and a working knowledge of perl (et al.) who may or may not have a political agenda....
I mean really... Assuming you had at most a 100k web page you would have to have some would grab that _A_LOT_ of times for that to even be an issue. However I believe there are utilities for such things.

Besides which, someone repeatedly loading a website leaves a huge trail behind them, it would be trivial to get their ISP account cancelled and you'd have a good chance of getting them arrested/fined for mischief if not more serious charges.

Basically... it's not a problem.

Thats what I've been told. I may use AIT Inc., which offers 30 GB for $18.95/mo only because I'm not sure how big my site will become, but it will make me feel a little safer too

Heres a simple solution just put a counter or stats program up and when it starts recording thousands of hit a day just take the page down until the person stops...

I would not worry about someone re-loading your page. If you optimize your web site, then you should not have a problem, and as others have mentioned, your log files will show this activity. If your site is text heavy, consider using mod_gzip with Apache to compress the data.

There are a lot of other more serious issues related to bandwidth consumption, e.g. graphics stealing -- many people may link to third party images directly, thus saving their own bandwidth and disk space.

Also, pounding a poorly written cgi-bin app will cause more problems than reloading a web page.

If you site gets really busy, then consider getting a dedicated server -- you can then block any offenders with IP firewalls.