National polling is irrelevant at this point in time. It is state polls that matter.
Which candidate can get to 270 Electors.
Here are the 22 states plus D.C. where Mr. Trump must make in-roads in order to stop Clinton: WA, OR, CA, HI, NM, CO, MN, WI, IL, MI, PA, NY, VT, NH, ME, MA, CT, RI, NJ, DE, MD, VA & DC would give her 273 Electoral votes.
National polling gives you a good idea which state polls are bogus and which ones are accurate though (eg: if you believe national is tied, no way is Clinton up 4 in GA like a poll that came out yesterday; alternatively if you believe Clinton is up nationally by 5, no way is Trump up by 4 in Ohio, 5 in FL and 5 in NV like a poll said yesterday)