Not lunacy, this is intentional. The agenda is to get an assault rifle ban and have the definition include as many weapons as possible. If the Rats get the Congress we will see an assault weapons ban if they don’t it is still likely. Incremental repeal of the 2nd is the plan.
They'll need a president to sign it into law, and barring that, they'll need the votes to over-ride a veto.
Even if the Dems somehow retake the House in the midterms, they won't get another AWB, and they know it.
At this time (and for the foreseeable future), all they can do is demagogue the issue. Americans, including a growing number of Dem voters, will not give up their guns or their 2nd Amendment rights.