While President Obama holds a 51% to 41% lead over Mitt Romney in a July 16-26 national poll of registered voters, the contest between them is much closer in the 12 states considered to be key battlegrounds in this year’s presidential election.

Obama holds only a four-point edge (48% to 44%) across 12 of this year’s key battleground states. The overall balance of support in these closely contested states has remained level in recent months, with Obama slightly ahead, but neither candidate holding a significant advantage.

The 12 states that are rated as tossup or lean Republican or Democrat are: Colorado, Florida, Iowa, Michigan, Missouri, Nevada, New Hampshire, North Carolina, Ohio, Pennsylvania, Virginia and Wisconsin. Read More

Russell Heimlich  is a former web developer at Pew Research Center.