It’s a win-win situation for everyone. Politicians declare their support for Bitcoin adoption by promising to facilitate cryptocurrency activities, which encourages more people to trust the market and thus trust politicians. Investors, in turn, benefit from this unspoken agreement and support politicians. Regardless of whether these promises are fulfilled or not, there is likely to be little results.
Politicians and their family members can take advantage of possible policies and get profit too. Like Trump as the USA. President Elect, publicly talked about his friendly plans for Bitcoin and cryptocurrencies. He did not hide that his family member are big fans and also investors in Bitcoin and cryptocurrencies.
Doing things with policies is very profitable, if you can do it successfully. Trump has many reasons for his family to open more space for Bitcoin and cryptocurrencies in the USA, but benefit for his nation is bigger too. Blockchain technology changed the world and will change it more, so a big nation like the USA. don't want to stay outside or see blockchain companies migrate from their nation to other countries because they have bad policies for this industry.
I can't understand what you mean by Trump's family. Do you mean his close family, i.e. his friends and relatives? I don't think that would be the motivation for adopting crypto-friendly policies anyway.
We have a previous experience with Trump in power, where his policies were not crypto-friendly and he did not contribute to supporting crypto even to a small degree. Now we have Trump supporting crypto in election promises to win the election, and we do not know what will happen after that. Hopefully, the influence of Elon Musk and J.Kennedy will help continue the adoption choice .