There are actually elements in the Republican party who are good for world peace. There are many who see themselves as conservatives who avoid the party and share their minority views. Unfortunately they are minority views ( or positions ) in terms of most of the party politicians.
In the main the picture is really bad. A big part of the problem is the way politicians in the US are so beholden to corporate and other special interests ( e.g. banking, arms industry, AIPAC ). Many Democrat politicians are as bad because of a combination of the same legalised corruption and because of fear of looking weak against Rep rivals.
A factor that makes the Reps look worse is the greater preponderance of religious posturing from their ranks. ( Fundamentalist religion has also been a real danger in the past and could be again ).
Absolutely yes, they are a danger, is my overall conclusion.