Case growth outpacing testing in coronavirus hotspots

The United States' alarming rise in coronavirus cases isn't due to increased testing — particularly not where cases have grown fastest over the last month.

Why it matters: The U.S. doesn't yet know what it looks like when a pandemic rages on relatively unchecked after the health system has become overwhelmed. It may be about to find out.

The big picture: The number of tests completed in the United States is going up, which is a good thing. But the number of new cases is increasing faster.

• The situation varies state by state, but the gap between testing and cases is generally largest in the cases with the fastest-growing coronavirus outbreaks, like Florida and Texas.
• But in some places, like the District of Columbia and New York, testing has grown faster than new cases — a good indicator that these outbreaks are under control.

My thought bubble: Even if testing did explain why America's official coronavirus caseload has doubled over the last month, that would be little cause for comfort; it'd only indicate that we have a worse problem than we'd thought.

• But the reality is that states like Arizona, Florida and Texas are struggling to meet the demand for coronavirus tests, meaning the pandemic is already outpacing those states' ability to respond to it.