The Democratic presidential candidates had their eleventy billionth debate Tuesday night. It was a largely uninformative and annoying affair, with the airhead CNN moderators asking loaded questions about when and where the candidates would be willing to start wars or assassinate people, but demanding answers about how new welfare programs would be paid for. (Twenty-year land wars in Asia are free, apparently.)

But one conclusion was clear: Sen. Bernie Sanders (I-Vt.) is the most consistently anti-Trump candidate — the one most willing to oppose his every move.

Of course, every candidate claimed to be committed to defeat President Trump by any means necessary. In his closing statement, billionaire Tom Steyer compared Trump to an athlete who was kicking his teammate — that is, the American people — in the face, perhaps implying he's the hockey enforcer candidate for 2020.

However, Sanders was the only one who stated that he would not support the U.S.-Mexico-Canada (USMCA) trade agreement passed out of the House. While he granted the agreement would provide some modest improvements relative to the status quo, he argued it was too small and weak to support. It's a fair position — in fact, he understated the case. As economist Dean Baker details, even an extremely generous study on this deal estimates that it would add 0.35 percent to GDP by 2034 — or a piddling 0.02 percent per year. More realistic considerations of automobile provisions alone would reverse that entirely. And as David Dayen writes at The American Prospect, USMCA also enshrines a legal shield (known as Section 230) for tech platforms that gives them legal immunity from content users generate — a seriously problematic provision that will now be much harder to alter in future.

Sanders did not say it outright, but his position is unquestionably the smartest move for the Democratic Party as a whole if they want to take the presidency in 2020. Giving the president a win on his signature policy issue during an election year is idiotic tactics — particularly when the win is so heavily compromised on the policy merits. Allowing Trump a victory might be worth stomaching if it's a big improvement, but handing Trump a massive rhetorical talking point in return for virtually nothing is dumb.

The smart move would be to run out the clock on the Trump presidency and pass something much better once Democrats have the run of government. Opposing USMCA is the kind of hard-nosed political tactic Sanders is supposedly incapable of but is actually quite good at.

Trump's conflict with Iran, and his destruction of the nuclear deal with that country, also came up in the debate. All candidates agreed that the nuclear deal should be rescued — the "nuclear deal with Iran was worked on with a number of our allies. We have got to undo what Trump did," Sanders said, while Sen. Amy Klobuchar (D-Minn.) said she "would start negotiations again."

However — perhaps because the CNN moderators asked preposterously belligerent questions trying to bait the candidates into saying under which conditions they would launch wars of aggression — Sanders' attempts to defeat a vote in Congress that undermined the nuclear deal was not mentioned. As Aída Chávez writes at The Intercept, back in 2017, before it had blown up the deal, the Trump administration was pushing a bill in Congress to add more sanctions to Iran, in part by coupling them to sanctions on Russia. This was a clear violation of the deal, and Sanders tried to stop the bill — arguing especially that it was horribly cruel to sanction Iran for no reason on the very same day the country had suffered a terrible terrorist attack — but to no avail. And while Obama administration veterans like John Kerry were out defending the deal, former Vice President Joe Biden — who was key in getting it passed in the first place — was "nowhere to be found," writes Chávez.

Sanders was the only remaining 2020 candidate — including Klobuchar and Sen. Elizabeth Warren (D-Mass.) — to vote against the sanctions.

Moderate #Resistance Democrats like to posture as though they will stop at nothing to defeat Trump. But when push comes to shove, their timid compromising nature shines through. Only stubborn radicals like Bernie Sanders will actually stick their necks out to oppose Trump even if it means annoying big donors or risking Wolf Blitzer calling them weak on national security. If Democrats are looking for the most principled anti-Trump candidate, the choice is clear.

Want more essential commentary and analysis like this delivered straight to your inbox? Sign up for The Week's "Today's best articles" newsletter here.