You said — “Nobody can see into the hearts of men. But... I’m suspicious about this guy.”
Well, hey! I’m not saying to not be suspicious of Obama, not at all. Hitler was a disaster and he wasn’t the Antichrist. Stalin was a brutal dictator and the murderer of millions of his own people and yet, he was not the Antichrist. There are many wicked and evil people in the world, including those who gain power (like Saddam Hussein for another example) and yet, they are not the Antichrist.
So, be suspicious about him and watch him like a hawk and oppose those policies that he’s putting forth — but he’s not the Antichrist...
How will we know the Antichrist?
I think you make a mistake in looking for antichrist in the form of a man. Hitler and Stalin had the spirit of antichrist. Obama has it. John promised that every spirit which does not confess (pro)Christ is antichrist. Evil is in the world and the enemies of God have been and will continue to persecute the people of God. That will doubtless intensify as we near that final glorious Day. But we KNOW how it ends!
Don't spend too much energy speculating, trying to fit world events into one possible interpretation of a heavily allegorical prophecy when you can be preparing and taking care of your family in the real world, and trusting God, and His providence. He is still and ever will be in control of it all.