Practice helps. So does being a stranger that’s visibly working class. I suspect you’ve run into a wall for being known and as a “hostile” for being a “liberal”.
At the time, I was very much a good young man who never claimed to be anything more than a moderate around these people. Those who knew me largely took it as what we might call 'debatelording' rather than seriously.
Me, having just led them by the nose to water and watching them not drink: "I'm just saying, you have to consider all sides of the issue."
"Whatabout whatabout whatabout? Ha ha ha, let's not talk politics anyway"
In any case, I stopped wasting my time years ago, and wear my socialism on my sleeve nowadays.