A majority of states do not approve of President Barack Obama's performance and his national approval rating is hovering just below 50 percent, according to a new Gallup Poll.

Obama's approval ratings range from a high of 83 percent in Washington, D.C. to a low of 27 percent in Idaho, with a substantial number of states clustered between 40 and 50 percent. His approval rating stood at 50 percent or higher in 16 states, an increase from the 12 states that registered 50 percent or higher approval ratings a year ago.

Comprising about 90,000 interviews conducted between January and June, the poll reflects Obama''s tenuous standing and the work he has ahead of him as he seeks a second term. He polled at between 45 and 48 percent in the perennially contested "battleground" states of Ohio, Florida and Pennsylvania, and his approval rating was in the mid-40s in Republican-leaning moderate states like Virginia, North Carolina and Colorado that Obama carried in 2008 and will target again in 2012.

Obama's national average of 47 percent also presages a potentially intense campaign. The poll's authors note that incumbent presidents typically need an approval rating of 50 percent or above to get re-elected, although President George W. Bush won re-election in 2004 with a 48 percent approval rating.