[Ed. – Not sure it’s quite this cut and dried.]
There’s an old Army adage, “The Commander is responsible for everything his unit does or fails to do.” That also applies to the President of these United States. The President gets the credit when things go right (except for Donald Trump) and gets the blame (except for Barack Obama) when things go wrong.
Ultimately, President Trump sits at the apex of the Executive Branch and is indeed responsible for any shortcomings, real or imagined of test supplies, equipment and process. It appears he takes that responsibility seriously. However, he was held back by longstanding regulations that prohibited rapid response to this crisis by Local and State authorities, especially when it came to testing procedures.
In a March 10, Article, the New York Times admitted that bureaucratic restrictions likely hindered rapid manufacture and distribution of test materials by local and state authorities.