The Democrats will sue, claiming that because they did not get as many votes as in years past, it therefore constitutes proof that the requirement for IDs inhibited voter participation. They should ask the judge for a specific number of votes as compensation, just to make things "fair."
Think of as equivalent to affirmative action among political parties.
The courts have already, repeatedly, upheld the PA Voter ID law.
To my knowledge, no other challenges are either in process or forthcoming.