For those new to the concept, Net Neutrality in its´ simplest definition Net Neutrality seeks to prevent the companies that provide internet access from restricting in any way what you can do on the internet. This includes anything that restricts the speed of access or blocks certain websites. The fear of course is that in many areas of the world, including parts of the USA, there are few choices, with sometimes only one company providing access to the internet and if that company also owned websites and other online properties, they could strangle competing websites by either blocking them or making them unbearably slow.
The real fight against net neutrality comes down to bandwidth, where internet service providers (ISPs) claim that file-sharing websites produce drastically more bandwidth demands than other websites and so the ISPs want to throttle traffic to and from file-sharing websites to ensure faster bandwidth for its customers that do not use file-sharing websites. It has yet to be proven if this is a legit concern if the use of file-sharing websites does actually cause other customers to have slower internet access.
The real issue is just that the laws that have been introduced so far have not been technically precise, meaning they are broad enough that while the purpose might be to throttle file-sharing websites, the laws, as written provide a very steep slippery slope that would allow ISPs to do much more than simply deal with file-sharing sites. They would give the ISPs broad discretion as to how to determine which websites to restrict. Most experts are very polarized regarding the issue, but the few who see both sides of the debate mostly agree that the real problem with eliminating Net Neutrality is that the powerful and rich ISPs in the USA would be able to continually buy politicians and constantly make things less restrictive for themselves. Once there is a crack in the wall, the wall crumbles quickly.
While for the most part, Net Neutrality is a bi-partisan thing, the sheer amount of lobbying and campaign financing done by a few large ISPs in the USA has resulted in several attempts over the years to allow cracks in Net Neutrality that have mostly all failed. This changed recently when President Trump appointed Ajit Pai as the chairman of the FCC. In the Obama administration, internet access was deemed to be a public utility which results in government oversight that guards Net Neutrality. Ajit Pai, on the other hand, has different concerns, claiming that putting ISPs under the oversight of the federal gov´t has caused a decrease in infrastructure spending by internet providers.
How does this affect online gambling? Well in multiple ways, the largest being that physical casino could work with ISPs to restrict online casinos who they see as a major threat. Some of the wealthiest people in the USA are casino owners in Las Vegas who lose billions to online gambling, it is not conceivable that they take large shares in some of the largest ISPs in order to make online casinos not available on certain networks.