(CNN) - For Barack Obama, the Democratic convention and the bump in the polls that is expected to follow couldn't come soon enough.
According to a new CNN poll of polls, the Illinois senator's once-comfortable lead over McCain is down to only 1 point nationwide - potentially troubling news for Obama as he gets set to accept his party's nomination in Denver.
Obama now leads McCain 45 percent to 44 percent, down from a 3-point margin in a CNN poll of polls yesterday and down from an 8-point lead in mid July.
The seemingly rapid drop in the polls could be due to the reemergence of national security issues following the crisis in Georgia, giving McCain an anvil to hammer away at Obama's inexperience. When Russian troops invaded Georgia two weeks ago, McCain vigorously denounced the action and warned of consequences. Obama's reaction was more measured, and potential voters noticed, CNN Senior Political Analyst Bill Schneider said.
"Which candidate do voters believe is better qualified to deal with Russia? McCain by better than 2-1," Schneider said. "More experience in military matters and foreign affairs."
CNN Election Center: Check out the latest polls
In a year when the Republican brand is reeling, CNN Senior Political Researcher Alan Silverleib says the Obama campaign officials should be concerned their lead appears to have become so tenuous.
“This ought to be a landslide Democratic year, but right now the Obama campaign is at risk of snatching defeat from the jaws of victory," Silverleib said. "They’ve been slow to respond as McCain has successfully raised a series of questions about Obama’s basic fitness for the presidency."
"The pressure is mounting for Obama to regain the initiative as he heads to Denver for what is certain to be one of the most critical weeks of his campaign
But can the Democratic presidential candidate rely on the post-convention bounce? Maybe. From 1976 to 2004 every major party nominee has gained ground - 8 points on average - in polls taken immediately after the convention. But in the last presidential cycle, neither President Bush nor Sen. John Kerry received any bounce from either of their conventions.