It would appear that on this occasion the statement from the White House sums it up pretty much entirely. Donald Trump is president anyway. He won the election and it makes little difference to him at this point whether or not vote cheating is investigated and litigated. It would have been nice if it was though.
Meanwhile there are bigger things developing. For example Paul Manafort is suing Mueller et al. That's a biggie. MBS has US mercenaries busy hanging much of the Saudi elite upside down as they assist with "enquiries". Sanctuary cities and illegal immigration is still an unresolved issue and it is heating up. Steve Bannon is reported to have dissed Jared, Ivanka, Don jr et al and by so doing has seriously called into question the actions, integrity, ethics and competence of the administration. That's a biggie.
Meanwhile US foreign policy has failed. US diplomacy is an international joke. The reputation of the US is at an all time low with allies, as well as enemies. The US dollar is rapidly being replaced and is not going to be world reserve currency for that much longer (that one is really going to hurt). The war in Afghanistan has been lost. The invasion of Iraq is now recognised to have been waged on lies (worse, it likely fits the legal definition of a hideous war crime). It is now known and proven fact that incredibly enough the US government has been supporting ISIS and Al Qaeda! Unfunded liabilities of the US government exceed US$222-trillion and continue to grow. Cities and states throughout the USA are insolvent, pension funds throughout the US are insolvent or very close to it. The middle-class is collapsing. Student delinquent debt has climbed to unsustainable levels, as has risky auto-finance.
All that is just for the entre. There is plenty, plenty more. Like unemployment, the rise of junk jobs, low productivity, destruction of manufacturing, a vast cohort of people back living in Ma and Pa Kettles' basement during what ought to be the prime years of their lives...
So, it might well be understandable that President Trump is a little busy with his attention directed towards other things. Kinda reckon there is plenty of stuff for him to be focussing upon right about now.