Remember a decade ago, when the right-wingers were complaining about “Rudy McRomney,” i.e., the prospect of the supposedly insufficiently conservative Rudy Giuliani, John McCain or Mitt Romney becoming the 2008 GOP nominee? The “Rudy McRomney” stuff didn’t make a lick of sense–Giuliani, McCain or Romney would have had to answer to the GOP’s right-wing base as President, and would have had to pacify those babies once they started crying.

There are key differences between the “Rudy McRomney” nonsense and the current kerfuffle over the supposedly insufficient progressivism of possible 2020 Democratic Presidential contenders Cory Booker, Kamala Harris and Deval Patrick. For one thing, those who are raising questions about how committed Booker, Harris and Patrick are to progressive principles simply want a Democratic President who will push the American political template to the left, just as Ronald Reagan pushed the American political template to the right. That is a noble goal. Having said that, one can certainly understand why Booker, Harris and Patrick might be reluctant to undergo the unrelenting scrutiny of the purity police.

Booker, Harris and Patrick have been assailed for their supposed reluctance to stand up to big-money special interests and/or their alleged deference to said interests in their professional lives. No one can credibly claim these three individuals are corrupt; rather, the allegations involve the appearance of moral impropriety with regard to the one percent.

Rather than waste time trying to defend their integrity to those who will forever suspect that they don’t have much, Booker, Harris and Patrick would be well within their rights to stop these sorts of attacks cold by announcing that they have no intention of running for President in 2020, forcing their critics to find a progressive hero without spot or wrinkle to embrace (if they haven’t embraced one already). After all, Barack Obama’s experiences prove that no good deed goes unpunished.

Obama still gets insufficient respect from the left for his accomplishments–the economy he resurrected, the wise federal judges he appointed, the class and nobility in public service he manifested. It’s still fashionable to say Obama “didn’t do enough”–didn’t do enough to hold accountable every last person responsible for the 2008 financial crash, didn’t do enough to press for a public option in the Affordable Care Act, didn’t do enough to challenge the tenets of right-wing ideology, etc., etc.

He may not have done enough, but damn it, he did plenty–in the face of unrelenting scorn from the right and tepid-at-best praise from the left. The same thing would happen, in all likelihood, to a President Booker, President Harris or President Patrick. Why even bother going through all that hell?

The attacks on Booker, Harris and Patrick are unquestionably pre-emptive strikes, efforts to ensure that no “DINO” becomes the Democratic nominee in 2020. There’s nothing wrong in allowing these pre-emptive strikes to work. Heck, Andrew Cuomo should also declare that he won’t run in 2020, rather than put up with endless attacks over his alleged disdain for progressives.

If an undisputed progressive secures the Democratic nomination in 2020, there will be no excuses. If that candidate wins, it will prove once and for all that the Democratic Party should not be afraid of embracing a bold progressive vision. If that candidate loses, then perhaps the country isn’t as progressive as we’d like to think it is. There’s only one way to test this theory out: have Booker, Harris, Patrick, Cuomo and every other Democrat of prominence whose progressive credentials have been repeatedly challenged simply sit out the 2020 Democratic primary, thus ensuring that only an undisputed progressive gets the Democratic nomination. Of course, one can’t help wondering: if that Democrat wins the presidency, will he or she also face criticism shortly after taking office for allegedly not being progressive enough?

D.R. Tucker

D. R. Tucker is a Massachusetts-based journalist who has served as the weekend contributor for the Washington Monthly since May 2014. He has also written for the Huffington Post, the Washington Spectator, the Metrowest Daily News, investigative journalist Brad Friedman's Brad Blog and environmental journalist Peter Sinclair's Climate Crocks.