Hamas is not the pro Palestinian organization that you think it is. They are religious fanatics that only care about killing Jews. Hamas never cared about Palestinians which is why they love to store ammo at the bottom of important buildings and launch rockets from apartment complexes.
They were out there beheading kids, shooting entire families and kidnapping people today. Commit pure acts of terror.
They came to power through violence after they lost an election. You should maybe go visit their wiki page and educate yourself on them.