It's basically all knotted up between President Barack Obama and presumptive Republican presidential nominee Mitt Romney, according to an average of three national surveys released over the past 24 hours.

A CNN Poll of Polls compiled and released Wednesday morning indicates that, on average, 47 percent of registered voters in the three surveys say they back Obama, with 45 percent supporting Romney, the former Massachusetts governor who is making his second bid for the White House. With Obama's two-point margin over Romney less than the sampling error of the surveys, it's fair to say that the race can be considered a dead heat.

The three surveys are from NBC News/Wall Street Journal (May 16-20), ABC News/Washington Post (May 17-20), and Gallup's daily tracking poll (May 15-21).

As the CNN Poll of Polls is an average of other surveys, there is no sampling error for the results.