Barack Obama, the charismatic former president, can cause a scene just by walking into a coffee shop, as the rapturous crowds in usually blase New York City demonstrated at one of his cameos. So as he gently re-entered the public and policy eye this week, it’s no surprise that he could throw both Democrats and Republicans off balance — though of course for very different reasons.

Senate Majority Leader Mitch McConnell gave President Donald Trump possibly his most important first-100-day achievement by spearheading the maneuver to transform Obama’s Supreme Court pick to replace Antonin Scalia into the conservative Neil Gorsuch, whose first significant vote allowed an Arkansas execution to proceed. McConnell’s obstruction and subsequent “nuclear option” may have played a part in breaking the democratic process, but isn’t that a small price to pay for a win — at least I’m sure the president feels that way.

The Republican Congress and a Republican president, through executive orders, laws and public statements, have focused on undoing the Obama legacy, from immigration reform to climate change to criminal justice. Their major impediment, on, for example, the Affordable Care Act, has been the fractures within the party itself.

The former president’s appearance this week at his pre-presidency hometown of Chicago, moderating a panel of young future leaders on community engagement, was not outwardly political. But of course it was, as all the values he holds dear and the issues he chose to champion in and out of the White House run counter to the GOP playbook. Even the setting, in a city Trump has demonized, sent a message.

McConnell, the man who stymied Obama time and time again, could not quite put him away by making him that one-term president, as he promised at the midpoint of Obama’s first term. In his reappearance on the public stage, can Obama do anything to halt the assault on his legacy?