(CNN)– Sen. John McCain is chipping away at Sen. Barack Obama lead in national polls.
According the latest CNN Poll of Polls, Obama now leads the Arizona senator by three points, 45 percent to 42 percent. Last Thursday's Poll of Polls showed the Illinois senator up by four points, 47 percent to McCain's 43 percent.
The latest CNN analysis of several recent surveys does not include any post Republican National Convention tallies.
"While the race appears to be tightening up a bit, it's worth keeping in mind that we still haven't seen any polling conducted after the Republican Convention," noted CNN Senior Political Researcher Alan Silverleib. "It's still too early to tell what - if any - bounce McCain will receive last week's GOP gathering in St. Paul. The jury's also still out on Sarah Palin, though there are certainly strong early indications that she has succeeded in energizing the Republican base."
The polls included in CNN's most recent Poll of Polls includes three surveys: CBS (September 1-3), Gallup (September 2-4), and Diageo/Hotline (September 2-4). The Poll of Polls does not have a sampling error.