Definitely. But they do visit rightist sites to spew hate. I see it often in the postings.
I do not do so to leftist sites, first because I do not favor such action, second because I know I would be effaced and banned.
Before C-Span had the Dem, Republican and Independent phone lines, phone calls were overwhelmingly from a conservative viewpoint. Then someone, in Florida IIRC, organized people on the left to assign people a monthly time to call in. Then came the designated lines. Then the calls became dominated by the left with many of the supposed Rs saying ..... I am an R, BUT in this case.... I stopped watching.