Calling the shots for the Democrats is Robert Bauer, another well-known Washington lawyer, who is a former Obama White House counsel and Democratic National Committee attorney. Bauer oversees hundreds of lawyers who have volunteered to set up shop in "boiler room" operations in battleground states and across the country.
Both sides will have local attorneys on the team as well.
The Obama campaign also has built up a computerized system to track Election Day incidents in real time. Democratic poll monitors and operatives can call in incidents as they occur and the computer-based system will quickly give campaign officials in Chicago the ability to track and compare the reports and respond quickly.
"No one's going to be flat-footed here, or for that matter anyplace else," said Stephen Hunter Johnson, general counsel to the Miami-Dade County Democratic Party. "Whatever the challenges are, we're up and ready."
Lawyers will observe at targeted polling places, joined by tea party activists and voting abuse critics on the Republican side and civil rights and union groups on the Democratic side. And in crucial battleground states such as Ohio, Florida, Wisconsin and Virginia, Republicans have added legal and political muscle from governors, secretaries of state and GOP-dominated legislatures.
Some legal skirmishes have already begun. Bauer, for instance, wrote this week to Wisconsin's secretary of state raising questions about reports that some Romney poll watchers were being trained with information that could mislead or intimidate voters. State officials said they did not find evidence of egregious transgressions, but the issue could resurface in a potential postelection legal fight.
Election law experts say it's most likely that litigation over the presidency would come down to Florida or Ohio and probably involve either absentee ballots or provisional votes, meaning those that must be verified later by local election officials for a variety of reasons, such as a voter showing up at the wrong precinct, not having proper identification or having their eligibility to vote called into question by a poll watcher.