Whatever members of Congress and their staffers may think about having to obtain their health insurance coverage through Obamacare, they’ll be providing a big boost to Washington, D.C.’s health insurance exchange.

For several years, members of Congress and their staffs remained in limbo due to a provision in the health care law inserted by Sen. Chuck Grassley, R-Iowa, forcing Congress to obtain their health insurance through Obamacare.

It had been unclear how the provision would be implemented, but last Wednesday, the Office of Personnel Management ruled that the federal government (in its capacity as an employer) could continue making contributions, on behalf of Capitol Hill workers, for coverage purchased on a new Obamacare insurance exchange.

The head of D.C.’s insurance exchange quickly said she was “thrilled” to be able to offer insurance to members of Congress, and this comes as no surprise.

Last November, the Washington Examiner’s editorial board met with members of the D.C. Health Benefits Exchange Authority. It was clear that one of their dominant concerns was whether there would be enough participants in D.C.’s exchange.

Experts have estimated that there needs to be a critical mass of at least 100,000 people in an exchange for it to be viable. But the District only has a population of about 632,000, many of whom either obtain insurance from their federal government employer, or D.C.’s generous Medicaid program, so the uninsured population is relatively low.

There was so much concern about the potential lack of participation in the exchanges, that they went further than any other exchange by adopting a rule to make the exchange the sole market for individuals and small businesses to purchase insurance.

Now, thanks to the OPM ruling, the D.C. exchange can expect to see a flood of thousands of Hill staffers, which will make it easier for the exchange to meet its participant threshold.