President Bush has gained ground on Democrat John Kerry (search) in the month of August because of "relatively small but unmistakable" shifts in the political environment, Democratic strategists said in a memo released Monday.

The polling memo by Democracy Corps (search), a group led by pollster Stan Greenberg and strategist James Carville (search), said the subtle gains by Bush have knotted the race again after Kerry had a slight advantage after the Democratic National Convention (search) in late July.

"There is no doubt that the Swift Boat Veterans for Truth (search) ads (attacking Kerry) have had an impact on the race," according to the Democracy Corps memo. Those attacks combined with the Summer Olympics have combined to "shift the focus away from Iraq and worrisome economic trends."

The Democracy Corps analysis averaged numerous national and state polls to come up with its assessment that Bush is doing slightly better against Kerry, a judgment supported more by internal measures such as issues and candidate qualities.