Of course, with 306 Electoral College votes assigned to Trump, it would only take 37 faithless GOP electors to block his presidency and push the election to Congress to decide.  Per Politico:

Lessig's anti-Trump group, "Electors Trust," has been offering pro bono legal counsel to Republican presidential electors considering ditching Trump and has been acting as a clearinghouse for electors to privately communicate their intentions.
 
"Obviously, whether an elector ultimately votes his or her conscience will depend in part upon whether there are enough doing the same. We now believe there are more than half the number needed to change the result seriously considering making that vote," Lessig said.
Meanwhile, the list of Democrat electors demanding an intelligence briefing on Russian interference in the election prior to casting their vote continues to grow.  As of last night we noted that 40 democrats had signed the petition and, as of this morning, the list has grown to 55.  Not surprisingly, the list is loaded with disaffected Hillary supporters from Democratic strongholds like California and Virginia.