It's a Grant reference. From the article...
General Ulysses S. Grant lost his first battle after being given command over all the Union forces. Rather than taking the lead of his predecessors and retreating, he gave a very famous order, "march to the left." In other words, we're not retreating, we're not retiring, we are going to engage the enemy across the entire line.
Ah, many thanks....I missed it..I was up late..couldn’t sleep, and the brain was fuzzy. We are so attuned to ideology, the “right” and the “left”..that I thought maybe something was fishy...LOL