...and they know that they cannot continue their actions (violence) if they want the support from the U.S. I do not see this as a bad thing long term. They were democratically elected. That shows the people that if the government does not give you what you want, you can vote them out. Now that Hamas is in, they are responsible for things that happen. Right now, they are no longer receiving U.S. support. They need the support in order to do what they need to do (rebuild, social programs, etc). Therefore, they will need to stop the violence in order to regain the support. This is a good thing. If they do not stop the violence, thereby not getting back the U.S. support they desperately need, then they will be voted out. This minimizes support for Hamas in the future. Again, this is a good thing.
Overall, I think that this is a good thing for them long-term. I see it reducing violence coming out of Hamas.