Your logic would be fine, except our candidate is Senator McCain.
On every issue we have huge problems with McCain (ie. campaign finance, immigration, enviro issue, etc), we would lose the same ground and more with either Hillary or Obama.
With McCain, we at least have a chance to hold some ground in the WOT, on abortion, on the SCOTUS, and with taxes. We know we would lose big time on all of those with Obama or Hillary too.