Is being liberal a good or bad thing?
In the simplest of terms, it doesn't matter.
Of course, it's much more complicated than just three words. Personally, I consider myself very liberal, but my opinions of my fellow leftists vary just as much as they do for those on the right.
About a year ago I visited some family members in Alabama for about a week. They lived in a small town: probably than 10,000 people and only three gas stations. It was a very rural and very conservative. Specifically, they were evangelicals. Nearly everyone was Presbyterian and went to mass on Sundays. But how were they as people? In short, fantastic. The folks on my family's street were very welcoming. the family next door even came over the day after we arrived to formally introduce themselves. HOWEVER: my brother, who is also very liberal, ended up in a conversation with a middle aged woman that got political. In short, word spread as fast as it does in small towns, and I caught a few dirty looks from people in church that Sunday.
My point is not that liberals are good with liberals or that conservatives are good with conservatives. That kind of opinion only fuels rhetoric that contributes to the polarization of society. What I take from my visit to Alabama is that these supposed ultra-conservatives did not care about where we were on the political spectrum - they treated us as human beings. It was only after we were recognized as liberals that some of them - and only some of them - began seeing us as bad people.
To summarize my point, it's counter-intuitive to make your political stance a part of your interactions with people. If, however, you are the kind of leftist that is more than ready to announce it, best of luck making too many conservative friends. It may sound a little "kumbayah," and, ironically, liberal of me to say so, but in the grand scheme of things, we are all humans and will be treated as such if we do the same to others.