Right now in the average of all polls at RealClearPolitics Hillary is up by 4.7%. Rasmussen polling is predicting Trump will win by 2%. At roughly the same point in the 2012 election cycle, Rasmussen was predicting Romney would win by 4%, and he ended up losing by 2.5%, meaning they were off in their polling by 6.5%.
How large do you think Hillary's margin of victory will be as a % of votes?
Nate Silver of FiveThirtyEight.com has HRC winning about 48% to 43% on votes and about 340 to 195 in the Electoral College.
While Silver did fail badly to foresee the rise of Trump as the GOP candidate, his polling predictions have been generally pretty solid, so barring a major election-altering event, I think Silver's number will be close to how things ultimately unfold.