You do not need to "get the judge to consider" what she is doing. It is something that judge has heard over and over and over if they've been in family court very long. They won't be unfamiliar with it, or have to see it proven yet again. That's why you should avoid the "parent alienation" term, though that is of course exactly what it sounds like she is doing. But it was used, overused, tried out to garner sympathy and make the user sound psychology-hep since its inception sometime in the 90's and it went out of style very quickly. It creates a slight gag response in everyone who hears it by now.
What I'd suggest, other than fully exercising your visitation to the letter, communicating with your ex only through the parenting message websites so you can't be sucked into any kind of fighting or arguing in front of the child, is that you maybe, in your time, have the child talk with a counselor to help him deal with his feelings and emotions, help him deal with his mother, who sounds like a tough person to be spending all his time with, someone who is manipulative and may have addiction issues. And if you are a recovering alcoholic, with issues of your own, you might profit from working through your issues too. As in, "See, son, this is what grown ups do, they talk to counselors and get help for when they feel angry and sad."
This will also look great to the courts and lay you some groundwork for if the situation changes, if you have reason to do so in the future, you may, at some point, need to take her back to court due to some change in circumstances and go for more or full custody. You need to always, to your son and the courts eventually portray yourself as the 'better man' the one of the parents who makes it a practice to be the adult, to follow the law, to not give in to hating and trashing the other parent, especially not in the presence or hearing of your child. It is better to make a complete liar out of her than to win the arguments.