Two people are arguing in public, you ignore them. Suddenly, one of them asks you, "Don't you think I'm right?" ~

If I were to become involved in that, and I'm not sure I would, or especially that anyone would even ask me, I would need to hear the arguments carefully before I could decide who I agreed with.  If I agreed with either. If not would express my own opinion. 

"I don't know. What are you taking about?"
And then go from there, I guess.

And, lately, most likely, worry about how I handled it.

It'd be best if I just tried to leave the situation gracefully.

I'll tell you like I did my mom when she and my dad were arguing. "Keep me out of this!"

It all depends on where I'm standing.....,plus they might even change places..... You just can't tell where people stand nowadays I think. !!......but mostly I don't    :( 

I would reply. Doo rock, ya knees nya you, in Russian, then look them up and down all inappropriately, then turn away, glancing back one or two times with even more inappropriate eye balling. 

Sorry I can't stop,  I'm late for jury service.

Two words:  No English

I would tell them it’s not my business and I’m not involved. I would have moved far away from both of them if I had the chance. 

"It'll cost ya.  How much money you got?"