With less than a week to go until the Republican National Convention, Mitt Romney and running mate Paul Ryan have some ground to cover as Barack Obama and Joe Biden maintain a healthy lead, according to recent NBC News / Wall Street Journal polls.

Overall, the polls place Obama and Biden four points ahead of their Republican opponents Romney and Ryan, with 48 percent to 44 percent apiece respectively.

However, the polls also showed a perhaps shocking result for Romney - while Obama has won over 94 percent of the African American vote, Romney has gotten zero percent.

Obama also maintains his lead among Latinos, people under 35 and female voters. Romney, however, leads in white voters, rural voters and senior citizens.

While Obama may hold an overall lead, analysts note that he is not yet in the clear and that Romney has a fighting chance. With both candidates under the 50 percent approval rating, it is nowhere near time to call a winner in what is shaping up to be a hotly competitive political battle.

In comparison to polls in June and July also conducted by NBC / WSJ, Obama has a slightly lesser lead over Romney in the 12 key swing states. In the earlier polls, Obama led by 8 points, but only leads by 3 points in the more recent statistics.

The comparison of polls between now and the June and July ones shows that Romney’s announcement of Paul Ryan as a running mate has had only a minor effect on his ratings. Prior to the Ryan announcement, there was a six point margin (49 percent to 43 percent) between Romney and Obama, and now there is a four percent split (48 percent to 44 percent).

Barack Obama and Mitt Romney to address the 2012 Clinton Global Initiative annual meetingGoogle Images