% pandoc --wrap=preserve -f html -t markdown
<h2>hi
there</h2>
^D
hi there
--------

% pandoc --wrap=preserve -f html -t markdown
<h2>hi <em>there
again</em></h2>
^D
hi *there again*
----------------

% pandoc --wrap=preserve -f html -t markdown
<h2>hi<br>there</h2>
^D
hi there
--------