Don’t argue. It comes across badly.
I’ve seen that it is the easiest way to throw a good case. I’ve seen too many people thinking that arguing with a key decision-maker or influencer is going to persuade them to back the case. It seems to have the opposite effect.
It creates unnecessary enemies.
A lot of lobbyists think that if they argue aggressively enough, they will persuade decision-makers and influencers. They could not be further from the truth.
If you want people to listen, try calmness and humour (backed with evidence).
Argument looks ugly and defensive. It suggests you know you are guilty. Like fast cars, it looks like you are compensating for the inadequacy of your case.
If you try humour and calmness, you are more likely to see your audience smile and laugh. Once they do that, they are more receptive, they’ll listen to you.
If you face a meeting or event where someone shouts you down, don’t shout back. Be calm and use civil wit.
If you use (aggressive) argument, you’ll come as unhinged and deranged. Everything you stand for will be painted with the same brush.
And, just because you don’t agree with someone on an issue does not mean you need to argue with them. Anyone who is married knows this.
Many years ago, in my militant federalist days, I debated the anti-European politician, Graham Riddick MP. I found civility and light humour far more effective a tool than his forceful moral indignation.
In meetings with politicians and officials, it is likely that you are not going to totally agree. That does not matter. If you start to argue with them, it is all but guaranteed that whatever gains you have won will be lost.
If one of your colleagues in a meeting goes rogue and starts aggressively arguing, pull the meeting immediately. Drag them out of the room, forcefully if necessary. Explain their sudden outburst down to the misalignment of the stars. If you don’t stop the meeting, you’ll face political ostracism.
The best lobbyists I know, keep calm when under aggressive attack. It helps. You find those who were lukewarm supporters, firm allies, and fence-sitters backing you. Mainstream opponents switch over to abstentions.
Some interests seem to use (aggressive) argument as a default strategy. It perhaps explains their lack of influence, inability to influence public policy, and win votes.
If your lobbyist can only argue, best pull them back from the front line. They are not serving your interests, they are harming them.