My ex wife has my daughter on medicaid, and I am wanting to claim her this year. Would I still be able to if my daughter is on medicaid?

Yes.  Your daughter being on medicaid will not prevent you from claiming her.  You can claim her if: 

• They're related to you.
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They're under the age of 19 (or 24 for full-time students).
  • No age limit for permanently and totally disabled children.
• They lived with you for more than half the year (exceptions apply).
• They didn't provide more than half of their own support for the year.

If she is 19+ or not a student, you can claim her if:

• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They lived with you the entire year.
• They made less than $4,200 in 2019.
• You provided more than half of their financial support.