There is no evidence because government did not raise the price - the insurance companies did, all while raking in record profits.

Premiums in states which refused federal money to expand Medicaid generally rose much, much more than states (like CA) which did not[1].

Cynically, this was likely a designed play by Republicans to kneecap the effectiveness of the ACA by skewing the risk pool towards the elderly (who require more medical care, in general).

[1] https://www.consumeraffairs.com/news/health-insurance-indust...