Mexico a Regional Power? 

I don't agree that Mexico is a Regional Power at least of Latin America, it could be a Regional Power of Central America, but nowadays it is considered to be part of North America.
In the other areas of the world, the article is divided between East, West, North, South not between ethnic or languagegroups. If this was the case in Europe it could be considered, Latin, Germanic, Slave and even Anglo-Saxon groups.
If we consider this, in the Americas case it should be South America and not Latin America.
Second case, Mexico has a great GDP but in overal terms GDP is not the only factor, we should consider military, power projection and foreign policy. Mexico has a ridiculous military and projection power and politically is a subalternous nation to the USA 
Argentina, Venezuela or Colombia have greater military and power projection capabilities, historically they have been much more interventionous and agressive toward other nations than Mexico and today we can see the same, specially in Venezuela case.

 16:11, 13 May 2007
Personally I agree with you, but you need sources to say it. This encyclopedia is not a place for Orignal Research. Furthemore, editors have produced sources saying Mexico is a Regional Power of Latin America, if we change it to South America there would be no place in wich to put Mexico. Besides, Brazil's influence is not restricted to South America, it would not make sense to say it is restricted since the sources don't agree.