Plant, finally slogged through
EXECUTIVE DEFENSE OF CONGRESSIONAL ACTS by S by DANIEL J. MELTZER (deputy counsel to the president from January 2009 through May 2010)
There is president although many more examples of defending.
the biggest he talks about are:
Not filing an amicus in Brown vs Board that I mentioned
Bush in the Metro case challenging the 1982 congressional amendment to the Communications Act of 1934 (p1202)
Clinton on Don't Ask, Don't Tell
Obama on DOMA
I'm not sure trump needs encouragement in breaking precedent but that actually was the argument Metzler made for always defending unless no justification
Here from pg 1228 in the original, pdf pg46:
$this->bbcode_second_pass_quote('', 'B')ut I
want to move the discussion to a higher level of generality, for I
believe the most critical question is the attractiveness of a regime in
which each administration views itself as having significant latitude to
refuse to enforce and defend acts of Congress. And I think such a
regime is likely to be less attractive than particular decisions or
theories, for a very simple but important reason: different
administrations are likely to have sharply different views about the
appropriate occasions for, and the appropriate theories underlying,
such decisions.
At the level of individual decisions, I heard it said that if the
George H.W. Bush administration would not defend what it viewed
as invidious reverse discrimination in Metro Broadcasting, the Obama
administration need not defend what it believes to be invidious
discrimination against gays. And one can well imagine that the failure
to defend DOMA could in turn be invoked as a reason for a future
Republican administration to refuse to defend some other statute in
the years ahead.
Not light reading but pretty interesting. He didn't defend Obama on DOMA and kinda raked Holder in fact. He did make a small defense about the decision not to defend Don't Ask.