A lot of people ask this question.
Bitcoin itself, cannot be regulated
What I mean by that is the government could not regulate Bitcoin on the base layer. Users will have the freedom to send it wherever without worrying about the transaction being blocked. You could get a Bitcoin wallet without needing to submit identification. You could still do p2p Bitcoin trades or in person Bitcoin trades.
Governments can regulate exchanges
This will make a harder barrier to entry for Bitcoin. The governments can regulate exchanges where people would go to actually go to buy their Bitcoin. In this sense, regulation likely would yield positive results in the long term. It legitimizes Bitcoin as an asset, and is welcoming to institutional investors.