The presidential race may be tightening, but Democrats are convinced they have an Election Day ace-in-the-hole: Hillary Clinton's ground game. They're confident it will withstand Donald Trump’s late surge in key battleground states. That’s according to The POLITICO Caucus — a panel of activists, strategists and operatives in 11 swing states, seven of which are seeing significant early- and absentee-voting operations. In those seven states where large numbers of voters are expected to cast their ballots before Election Day — Colorado, Florida, Iowa, Nevada, North Carolina, Ohio and Wisconsin — more than three-quarters of Democrats think their party has done...