“I’ll give just one reason for now: Obama said he was 3 months old when the bay of pigs happened, which was April 1961, making his birthdate January 1961.”
Not to quibble, but Obama doesn’t exactly have a pristine track record when it comes to dating historical events in relationship to his own personal life.
http://www.talkleft.com/story/2007/3/5/201426/5656
You may well have other legitimate reasons for believing he was born in January 1961, but I would argue that Obama’s claims about his birth are a pretty unreliable source of evidence.