What’s vexing is that Herchell Talan of North Kingstown has the basic principle right but comes to a statist conclusion anyway:

In the past 13 years, health-insurance companies have merged with each other at a frightening rate, and now a small number of companies dominate local markets. Rhode Island basically has two insurers: Blue Cross and Blue Shield of Rhode Island and United HealthCare. The data in the report show how much of states’ markets are controlled by one insurance company. Indeed, 94 percent of insurance markets in America are controlled by one or two companies, a near-monopoly under Department of Justice definitions.
We need more competition. By giving us a choice of a public health-insurance plan that’s available to everyone, Congress can break the insurance industry’s monopoly.
A choice of public health-insurance plans is good for consumers. It will let us choose the plan that meets our needs the best. More competition and choice means more efficiency as insurance plans compete and prices go down.

The government doesn’t operate like a private company; competitive forces don’t affect it the same way, and neither does its activity affect those forces in the same way. For one thing, a given activity of government doesn’t have to be profitable to persist, which is why statists like it so much, because it enables the perpetuation of favored policies even when those policies prove a drain.
The remedy for monopolies (as we’ve seen in other industries) is to break them up, not to introduce a larger player that doesn’t have to meet basic competitive standards. It is all but inevitable that government healthcare will draw the market toward itself until it is a true monopolist. Somehow, I suspect that’s not an outcome that Talan fears.