There are two ways of reading this data. The first is to say that Barack Obama is the most polarizing president since Dwight Eisenhower. The second is to say that Barack Obama exists in the most polarized atmosphere of any president since Dwight Eisenhower. If the former has the added benefit of assisting those who want to make a point about Obama's supposed radicalism, the latter has the virtue of being true, or at least better reflecting recent political history.
Eisenhower was president in an era where both parties had large and opposing ideological factions. Bipartisanship was a necessary fact of legislating, and as such, few votes broke down on party lines. Insofar that there was polarization, it was regional; Democrats continued to reign in the South, while Republicans made their home in the North and West. By contrast, Obama serves at a time when the parties are disciplined, organizationally unified (including local and state parties), and ideologically coherent. There are few conservatives in the Democratic Party, and almost no liberals in the GOP. Partisans on both ends are energized, and an infrastructure exists to promote their views in the public sphere (though obviously, this is more true for the right).
It doesn't matter that Obama extended conservative tax cuts for high-income earners or supports a cut in the corporate income tax rate. Insofar that he polarizes, it's because he's a Democrat. Short of resigning and bringing in a Republican to replace him, there is very little he can do to gain more conservative support.
Put another way, if their places were reversed, and Eisenhower were a Democratic president in 2011, it's almost certainly true that he would be the most polarizing president since Barack Obama.
