WASHINGTON – The slow growth reported for the second quarter is enough to allow President Obama an edge in his re-election bid, according to a forecasting model based on the economy and polling data.

The U.S. economy grew at a 1.5 percent annual rate from April through June, in line with forecasts and slowing from a revised 2.0 percent rate during the first three months of the year, the Commerce Department reported Friday.

“It puts Obama just barely above the break-even point,” said Alan Abramowitz, a political science professor at Emory University in Atlanta and developer of the forecasting model. “Mainly it tells me we’re heading to a very close election and Obama is a slight favorite.”

Abramowitz said Friday his model projects Obama will receive 50.5 percent of the popular vote in November and has a two-thirds probability of winning.

The model doesn’t project the Electoral College outcome, and it is possible to win the popular vote without an electoral-vote victory, as occurred in the 2000 contest between Al Gore and George W. Bush.

In three-quarters of the 16 presidential elections since World War II, the outcome has been within 1.5 percentage points of this model’s projection, Abramowitz said.

The forecast is based on the initial second-quarter gross domestic product report and the Gallup Poll’s presidential job-approval rating for the last three days of June, when the figure for Obama was 48 percent.

Abramowitz uses GDP as a broad measure of the economy and second-quarter data because the political impact of earlier economic performance already is reflected in public opinion polling.

Third-quarter GDP growth is no better than second-quarter growth as a predictor of an election outcome, and by the time it is available polling data alone is a superior predictor, Abramowitz said.

The first estimate of third-quarter growth this year will be released Oct. 26 – 11 days before the election.