Years ago I had association insurance via my bank.
Supposedly this offered me a lower price on Blue Cross insurance because those bank customers who wanted ths insurance were banding together.
I got it after having tried individual insurance through another company and discovering it was a battle to get reimbursed whenever I had healthcare costs.
But the association insurance
1) didn't cover pre-existing conditions except after a long waiting period,
2) seemed to reject more claims than Blue Cross rejected when I'd had it through employers, and
3) had steep increases in prices, close to 100% over a few years.
Trump and Rand Paul can spout all the nonsense they want about how these associations will supposedly save the healthcare system.
But unless the associations are already set up, very carefully -- and regulated by the government to prevent abuses -- telling people it's okay to destroy the ACA because the government will permit associations is equivalent to telling people to jump out of a plane without a parachute because one can be produced and delivered on the way down.