A quick answer:
While there doesnt seem to be data readily available, there is commentary from several news sources on the web.
Using the search terms Obama, African Americans and barriers I found these news stories, that may be in the direction of your research. If you clarify your question a bit, we can research some more.
Is Obama Black Enough? - TIME
http://www.time.com/time/nation/article/0,8599,1584736,00.html
Fewer than half of Americans say Obama's election has improved race relations- LA Times
http://www.latimes.com/news/nationworld/nation/la-na-obama-race-poll10-2009nov10,0,6623771.story
U.S. Waiting for Race Relations to Improve Under Obama- Gallup
http://www.gallup.com/poll/124181/U.S.-Waiting-Race-Relations-Improve-Obama.aspx?CSTS=alert
Obama to NAACP: Progress made but much still to accomplish
