Reagan's persistence led the way for the downfall of Obama's cherished Soviet Union. Reagan on Mt. Rushmore long before we have to look at the back of Obama's head on Mt. Rushmore. Obama isn't good enough to shine Reagan's shoes!
Obama while breaking ground as the first minority President has done nothing (yet) historically significant.
Washington: commanded revolution, precedent for stable leadership. Franklin:got the French on our side, which was decisive. Jefferson: the Declaration. Sam Houston: opened western expansion leading to continental United States. Lincoln: precipitated and ended the Civil War. TDR: the biggest civil project in world history - the Panama Canal. FDR: Depression and WWII leadership. Reagan: won the Cold War which had threatened the entire world.
I could add James Polk and Andrew Jackson and LBJ.
Obama doesn't make the Top Ten. Not so far.
Learn some history.