He was a partner at Foley & Lardner in Milwaukee, where he focused on commercial litigation and dispute resolution and chaired the firm's pro bono practice.

President Trump nominated Ludwig to the seat vacated by Judge Rudolph T. Randa, who assumed senior status on February 5, 2016.

However, Ludwig rejected that argument stating Trump's claim "confuses and conflates the 'Manner' of appointing presidential electors—popular election—with underlying rules of election administration.

"[10] Ludwig noted that the Electors were chosen based on the winner of the state popular vote, the manner established by the Wisconsin Legislature.

In his decision, Ludwig regularly noted the "extraordinary" nature of the case and what Trump was asking for in relief.

A sitting president who did not prevail in his bid for reelection has asked for federal court help in setting aside the popular vote based on disputed issues of election administration, issues he plainly could have raised before the vote occurred.