The political leaders are changed by elections. Power just keeps on doing what it wants, in slightly different contexts depending on who runs Congress or who is in the White House, but power mostly operates behind those forces and doesn't change hands with elections. It's been that way for some time now, and gets more entrenched with each election where we don't address it.
Foreign policy (both military and covert), domestic "security" issues, corporate access to government, the financial industry, thy give up noting without a massive fight from the citizens, and maybe not even then (Occupy was an attempt to address this, and was brutally put down, under a Democratic administration).
Until more people realize this and are willing to call it out, fighting for real change rather than the token changes power concedes, we live at their mercy.
And it isn't even just about us. The entire planet is under the thumb of the forces that run our government behind the scenes, using our tax-dollars to finance the military and paramilitary that imposes its will everywhere. U.S. citizens get blamed for their actions, though nobody asks us citizens if we approve of their actions, that's "off the table" (or under the table).
Sad to see ignorance or just complicity displayed in this thread by some. The truth is ugly, but it is the truth nonetheless. The greatest among us acknowledge it rather than ridiculing it.