It’s sometimes hard to tell, and the nearer you are to the “coalface”, the harder it can be. Here’s a few pointers (for more see How to Win Campaigns: Communications for Change).
First off, forget the debate. It only takes two to sustain a debate, which tells you not a lot. Instead, get some perspective from friends or even critics who are a step or three away but best of all, from insiders, whether directly or indirectly. Next, if you are not being completely ignored, you may be starting to have an effect. If they sound defensive, if they have lost a supporter or more, or if they are attacking you, then you are making an impact.
Signs that you are really winning begin when they start talking to others, especially those in greater authority (including media and public), and contesting your right to win. They must be thinking that you might win, to do this. A period of unexplained silence may indicate a change of mind or regime. If this is followed by rumours that they are exploring alternatives of some kind, then you are a bit further down the track: it’s the search for an exit strategy.
Finally, a change of language and attempts at positive engagement, and talking down the differences you have with them, indicate an imminent u-turn. It’s then a calculation as to whether you want to let them work with others on ‘solutions’ or, which is usually the best outcome, to convert them to allies. Don’t expect however to get your opponent to hoist a white flag – campaigns are wars of persuasion, not of force. And seeking to humiliate your erstwhile opponent is not a good idea. You will usually lose friends, allies and influence that way. How to tell if you are Winning