Because he was being more "flexible" as he promised them before the 2012 election.
Why didn’t Obama and his team want to stop Russian hacking? Originally Posted by IIFFOFRDB
The other factually accurate reason may be that the "Russians" were also staging anti-Trump demonstrations, which the DNC found "helpful" (they thought!).
Also, they just "knew" they were going to win! Remember the Eccie Pundits!