A new opinion poll released late Thursday reveals that U.S. President Barack Obama has a seven point lead over his Republican challenger Mitt Romney, with 52 percent of Americans saying they would re-elect the president and 45 percent opting for his rival. New figures show the Republican presidential hopeful Mitt Romney's unfavorable rating spiked as more Americans question his proposed economic policies. However, according to a CNN/ORC International survey, Romney supporters have jumped nearly ten percent compared to four months ago, up to 56 percent of strong supporters from 47 percent in May. Meanwhile, 67 percent said they strongly support Obama. Romney's' favorable rating remains at 47 percent, compared to 48 percent in July, and unfavorable rating spiked from 42 percent last month to 48 percent. He is lagging behind the president's steady 56 percent-42 percent favorable-unfavorable rating. Sixty-four percent of all Americans think Romney favors the rich over the middle class. And 63 percent of the public thinks Romney should release more tax returns than he has already made public. Regardless of which candidate they support, 63 percent think Obama will win re-election, with one third saying Romney will win. Separately, the survey showed 45 percent say the country would be better off if Congress were controlled by Democrats, with 39 percent saying things would be better if the GOP ran Capitol Hill. The CNN poll was conducted by ORC International August 7-8, with 1,010 adults nationwide, including 911 registered voters, questioned by telephone. The survey's overall sampling error is plus or minus three percentage points.