Jostling for position in the 2020 Democratic primary has started already, God help us. And there is probably no way around a bitter fight between liberals and leftists over who is going to be the nominee.

However, it might be possible to head off some of the bitterness that resulted from the 2016 primary by admitting the necessity of that fight and making it about ideology and policy to the greatest possible degree.

The first big flare-up of 2020 has already happened, over Beto O'Rourke. The failed Texas senate candidate got a ton of positive media attention during his campaign, leading to him being put forward by former Obama staffers as a good presidential candidate. Various lefties expressed some skepticism of this: Zaid Jilani and Branko Marcetic focused on his moderate policy record, particularly his support of financial deregulation, while I focused on how neither O'Rourke nor his Obamaworld supporters have deeply reckoned with the appalling consequences of the too-small stimulus or the corrupt bank bailout.

It really got going when Elizabeth Bruenig wrote a much more gentle criticism in The Washington Post. She argued that while O'Rourke is well above average when it comes to a possible Texas Democratic senator, he isn't the kind of full-throated progressive we should ask for, since about anyone should be able to defeat Trump.

A few big-shot liberals immediately spied a conspiracy. Center for American Progress President Neera Tanden wrote this on Twitter:

In Esquire, Charles Pierce wrote that Sanders himself must have been involved: "[T]here appears to be a concerted effort from the Bernie Sanders camp to paint O'Rourke as a tool of the oil and gas industry … That this comes on the heels of the Sanders Foundation's hootenanny up in Burlington is no accident." He concluded that the left is trying to clear the decks for Sanders to win the primary.

As an initial matter, it is pretty rich to see the president of the most powerful liberal think tank — whose major reason for existing is to coordinate policy and messaging for the Democratic Party — fretting about other people "orchestrating" messaging. And while I can't speak for anyone else, Bernie Sanders is certainly not giving me daily sealed marching orders.

But more importantly, viewing a handful of Beto-skeptical takes as an attempt to "clear the field" is ludicrous. Hillary Clinton cleared the field in 2016 by snapping up virtually all the party endorsements and big money donors. That kind of insider power elite maneuvering — not writing ephemeral internet op-eds — is the only way to actually stop others from competing for the world's most powerful office.

It's also worth noting what an outright disaster this virtual coronation was. When it became clear by late 2015 that Clinton was incredibly unpopular, there was no one to take her place besides Sanders, who was miles behind and didn't manage to catch up. It's possible Trump is president now because of it.

So the policy critiques of O'Rourke were simply the first salvo in a necessary primary battle. Now, in my view, it would be a lot better for liberals to respond in kind, by defending O'Rourke record on the merits, or perhaps attacking Sanders' record (or that of Elizabeth Warren), instead of speculating about putative online Red Guard cells. Since there is no avoiding policy and ideology, let's have that fight — in every state and over every inch of political ground.

This doesn't need to be some gentlemanly parlor discussion, where everyone agrees to disagree and shake hands afterwards. The politics of health care, financial regulation, foreign policy, and so on have enormous moral stakes. Liberals and leftists generally disagree on Medicare-for-all versus ObamaCare, whether big banks should be broken up, whether America's imperial machinery should be drastically scaled back, and much more. It will likely get pretty heated and personal, and that is simply to be expected.

It also can't just be policy details alone — there is probably no way of keeping various personal stories and dirt out of it. But those should also be a topic of discussion, if for no other reason that they will certainly be raised by Trump and his Republican toadies, and whoever faces him should be ready for it. All-out personal feuding is poor strategy, as it may depress turnout on the left, but neither should people's foibles be considered out of bounds.

At any rate, it's going to be a rough 18 months or so before someone comes out on top. But there is no way out but through. Let's lace up and slug it out.