Just a heads up that Trump is currently at +194.4 and Hillary is at -190.5. If you bet both sides, you can guarantee an ROI of .46%. Not a huge return, but it's "pretty much" guaranteed. I say pretty much because the way you could lose is if someone other than Trump or Hillary wins.
The other way you could play it is put money on Trump now. I expect the lines to converge closer to even money as we get closer to the election. And then you put money on Clinton later on.