Walsh was twice as Trumpy as the president until about 45 seconds ago. Fellow primary contender Bill Weld would alienate both pro-life voters and libertarians still annoyed at the former libertarian running mate’s betrayal of Gary Johnson. The perfect primary challenger would have to not alienate specific political factions, such as pro-life Americans, but more importantly, they would have to make the one affirmative political case that neither Trump nor the Left will: the merits of free trade and responsible spending.
The insurgent powers on the Left and Right both espouse the same sort of protectionism and disregard for the deficit that has the country careening towards a crisis. Trump, Bernie, and Warren all oppose NAFTA, love spending increases, and treat taxes like political tools rather than a means to pay for our national expenses.
For all the focus on what persona would be compelling, perhaps more important is a candidate with a differentiating message. Obviously, publicity matters, but South Bend, Indiana, Mayor Pete Buttigieg managed to catapult himself into the top five in his primary. And literally no one knew who Andrew Yang was until a few months ago, yet he’s broken into the top 10 of the primary with a single economic message about automation.