Anti-trust. Good point. I hadn't considered that angle. So why spend more than a billion dollars on lobbying and astroturfing just to get Title II restrictions lifted? The only way I can see for them to make money from that deregulation is by charging higher fees for higher priority traffic. And since they can charge both ends of the transaction - the consumer for the fast connection, and the web site for the fast connection - they stand to make back 100x that billion dollars they spent to get one niggling detail altered in the regulations. I just don't see where you get a 100x payback on a billion dollar investment, otherwise... and if they aren't in it for the expanded pofits, why go through the colossal expense and effort to repeal Title II? The whole Net Neutrality thing is a staying action, not a victory and they know it and the longer they can keep the government from making them behave like a utility the more money they make.
Comcast's operating income was $26 billion in 2016. Presume for the sake of argument that they paid all the lobbying. $1b represents 4% of their income. Presume they bump their rates 10% for one year. Their ROI on lobbying is over 100%. The broadband industry's revenue in 2016 was $140b. That's expected to drop $3b by 2020. A $1b lobbying push, if it so much as closes the gap left by catv subscription attrition, is more than a sound business decision, it's a no-brainer.