The 13 states and District of Columbia with majorities approving of Obama's job performance in the first half of 2012 is a slight increase from Obama's 2011 totals, as all 10 states with 50% or greater approval in 2011 remained at that level and were joined by Rhode Island, Washington state, and Minnesota. Additionally, Obama's approval rating fell just below the majority approval threshold in Michigan and Wisconsin, two key swing states this presidential election year. Six other states had approval ratings of 46% or 47%.

The 50% approval mark is significant because post-World War II incumbent presidents who have been above 50% job approval on Election Day were easily re-elected. Presidents with approval ratings below 50% have more uncertain re-election prospects. Historically, two presidents below 50% in their final approval rating before the election -- George W. Bush and Harry Truman -- won, and three, Gerald Ford, Jimmy Carter, and George H.W. Bush, lost.

From January to June of this year, Gallup asked more than 90,000 U.S. adults whether they approved or disapproved of the job Obama is doing as president. Nationwide, 46% of Americans approved and 46% disapproved during this time. Gallup interviewed at least 500 residents in 41 states and at least 1,000 residents in 32 states in the first half of the year. Gallup weights each state sample according to U.S. Census parameters to ensure it is demographically representative of that state's adult population.

Obama Does Well in Rich Electoral Vote States

Obama's approval rating by state can give a rough indication of how the Electoral College vote might look this fall. Voters' evaluations of how Obama has performed as president will arguably be the most important factor in determining their vote. The ultimate outcome in each state will also be dependent on voter turnout and how voters evaluate Mitt Romney as a potential alternative to Obama as president.

It is certainly possible that voters' evaluations of Obama in various states could be more positive or less positive on Election Day than they were during January through June of this election year. However, presidents' approval ratings on the national level historically haven't changed much in the final few months before the election.

The list of states in which Obama had majority approval during the first half of the year includes three of the largest states -- California, New York, and Illinois. This helps boost the combined Electoral College vote of states with majority approval of Obama to a total of 185. All of these states have voted reliably for Democratic presidential candidates in recent elections.

Most of the 16 states in which Obama's approval rating is below 40% tend to be smaller in population and thus have fewer electoral votes. The largest of these are Tennessee and Indiana with 11 electoral votes each. The 16 states with approval ratings lower than 40% total 93 electoral votes, and typically have supported Republican presidential candidates in recent elections.

That leaves 21 states in which Obama's approval rating is between 40% and 50%, including some of the largest "swing states" such as Florida (46%), Pennsylvania (46%), and Ohio (44%).

Geographic Patterns in Approval Consistent With Past

Obama's approval ratings tend to be highest in the Northeastern part of the country and in Pacific Coast states; they tend to be lowest in the Mountain West and below average in the South and the Plains region. These geographic patterns generally mirror what Gallup has found for Obama's approval rating in past years. They also tend to mirror historical state voting patterns in presidential elections.

Implications

U.S. registered voters remain closely divided in their current presidential vote preferences between Obama and Romney. In such a close race, the opinions of voters in a few crucial states could tip the balance in either candidate's favor.

If Obama were to win in the states in which a majority of residents approved of the job he was doing across the first six months of the year, he would have roughly two-thirds of the electoral votes he would need to be re-elected. That seems a reasonable possibility, given that those states have generally voted for the Democratic candidate in recent presidential elections.

Under that scenario, Obama would then need roughly 90 more electoral votes to win re-election. Whether he can reach that total will depend on how those in key swing states, particularly Michigan, Wisconsin, Florida, Virginia, and Pennsylvania, view him, and whether turnout of those who approve of him in those states exceeds turnout of those who disapprove.

Explore President Obama's approval ratings in depth and compare them with those of past presidents in the Gallup Presidential Job Approval Center.