SEGA don't need a kickstarter to be able to fund a sequel.
SEGA announced quite recently that Yakuza 5 will be released outside of Japan, 2.5 years after the japanese release. They don't do this because of any kickstarter, but because the loud voices of the fans who kept begging for it for years. Fans who sent them real letters, fans who participated in Sony polls of "what japanese game do you want to see released in the west the most" and so on.
So what's needed is not a kickstarter, but Alpha Protocol fans to be able to organise themselves into a loud strong voice. Some Facebook group with a couple of thousands of members would be a great start.
A kickstarter might be the way to go if Obsidian Entertainment wanted to make a spiritual successor of Alpha Protocol, though. But I also think that kind of kickstarter would need noticeably more money than they got with their https://www.kickstarter.com/projects/obsidian/project-eternity.
In the meantime, you could always play http://www.gog.com/game/sid_meiers_covert_action a bit