Instead, just say that there exists a type of person who holds a viewpoint, without referencing yourself as agreeing with it. Or state that "Some would disagree and say...."
For example, there's a thread where people are debating how alcohol impacts society. There seems to be a lot of "if you oppose parents who sponsor alcohol parties for underage kids in their homes, it's just because you struggle with alcoholism yourself."
You feel that is an unfair assessment, so you state "A person who is opposed to alcohol for teenagers may not necessarily be a recovering alcoholic. They may just feel that alcohol abuse causes more trouble in society than soda pop, and kids should wait until they reach the legal age to drink."
When a hostile advocate of teen drinking parties accuses you of being an uptight jerk, and rants about how young people drink alcohol in Europe, you can then counter by saying, "I didn't say I myself felt that way. I just said that there is that point of view, some people hold it, and I didn't think that angle was being considered in this discussion."
Or "Your point of view is often refuted by those who say....."
When you distance yourself from all viewpoints, and make assertions in an objective manner, you defuse a lot of the explosives in an argument.
Phrases that can come in handy include: "some people believe that..." and "there are some reputable specialists in this field who would say that...." and "another point of view I've seen expressed states that..." and "have you considered the position that certain other people might have on this issue?" as impersonalized expressions of alternate perspectives.
People tend to want to attack the person, rather than discuss the idea they present. You make that impossible when you refuse to be cornered. You remain mysterious, not taking sides, but suggesting a viewpoint that is not being considered.
This may anger some people. They may even demand, "Well, do YOU hold that opinion yourself?"
They want to drag you into the fight in a personal way, so they can attack you directly, which is easier than attacking some nebulous abstract mass of individuals.
They can't throw verbal stones at "other people" who are not in the debate individually, so they hope they can get you to divulge yourself to represent this contrary view, and then they can start stoning you personally.
Don't let them trick you into making the argument personal. Remain aloof, above the fray, detached from personal investment in a specific opinion.
If a combative person can get you to reveal how you personally feel about something, that gives them the opportunity to start bashing you, labeling you, and dismissing you as "just another left wing / right wing fanatic" or whatever the category may be that they want to demonize.
This technique of Expressing Impersonalized Opinions can be of great value when you feel like saying something, but know that tempers are hot -- and some of the participants in the discussion are acting childishly, or may even be trolls just trying to make people upset.
I consider this technique to be one of the most effective and important tools in online discussions that you will ever discover. I base this on my vigorous engagement in blogocombat since my entry into the realm in May 2005. That's when I started my infamous Vaspers the Grate blog. I retired it some years back, partly because people thought "Grate" meant "great, terrific, fantastic" (but it meant "abrasive") -- and now I blog in the persona of the Pluperfecter.