On the forum that I usually frequent, I am not very popular, and....most of my posts seem to get ignored....or my post might bring discussion to an end.
Other posters who agree with your opinion, may not be all that inclined to post solely for the sake of supporting your comments, especially if you've made your point especially well.
Conversely, you probably won't convinced those who disagree with you, of anything, but you may have posted a strong enough argument to persuade them to stand down.
If you are motivated to post on a bipartisan politics forum in the hope of receiving validation or reinforcement, you are probably going to be disappointed. Some other motivation is required to post on a site like this, I think. It is easier to post on a partisan site, but it can be pretty boring, too. I enjoy the challenge of seeing my arguments tested, countered, ridiculed, and when, for a challenger.....substance fails, it is even sometimes interesting to be subjected to personal attacks.
There is something to be said for simply learning how to "hold your own" in a political discussion.