In three polls Clinton's 4-point lead remains unchanged (on the average) reports Steve Benen at MSNBC/Maddow Blog.
NBC News/Wall Street Journal: Clinton 46 to 41
ABC News/Washington Post: Clinton 47 to 43
CNN: Clinton 49 to 42
And so, on the eve of the Republicans’ convention, Clinton’s lead is getting smaller in one poll, getting bigger in another, and staying the same in a third. When we talk about the importance of averages, this is why.
Note, each of these polls was conducted after FBI Director James Comey condemned Clinton’s email server protocols, leading to brutal media coverage of the Democrat. The story is widely seen as having taken a toll on Clinton’s support.