The possibility of a Federal mandate for retirement coverage through an employer plan or forcing the employer into an IRA program, which has been done through state and local governments will prop up pooled employer plans (PEPs).
The reason is simple: employers won’t want to be involved with a government-run plan and a better option than any IRA program is a 401(k) pooled employer plan because there will be more fiduciary work born by plan providers, as well as more retirement savings offered in a 401(k) plan than an IRA.