If Tuesday was, as NBC’s “First Read” said before the vote counts started coming in, the “biggest 2018 primary test” for the Democrats, then it appears they passed. Although ballots are still being counted and will be for at least several more days, it appears unlikely that Democrats are going to give away any House opportunities in California by being locked out under the top-two system.

This wasn’t misplaced hype; Tuesday was a real challenge for Democrats. Could party actors — politicians, campaign and governing professionals, activists and donors, formal party organizations, party-aligned interest groups, party-aligned media — figure out which candidates to support, and could they then transmit those preferences to voters and convince them to support the party’s decision?

Each step of that — deciding, transmitting, influencing — presented real problems in the context of the top-two primary. Deciding is difficult (as we saw during the 2016 Republican presidential nomination contest) in expanded, networked parties because there’s nothing even remotely like a formal hierarchy. Not only is there no one in charge, but there’s also not even any kind of formal mechanism through which the various party actors can collectively reach a decision. Then getting the attention of voters is always difficult, especially for down-party races. And it’s ultimately up to the voters whether to follow party cues — even if those cues are loud and clear.

And yet, in state after state throughout this year’s primary season, the party appears to be doing all of that well enough to get acceptable results. In most cases, the party even seems to be getting exactly the nominee it wants — assuming, that is, we can figure out the party’s preference. And in virtually all races so far for which disaster seemed possible, it’s been averted.

We also got a good example in California of how holding the White House can help. Republicans were in danger of getting locked out of the November ballot in the contest for governor. With five candidates on the ballot, none of them well-known or thought to be particularly impressive, it seemed quite possible that the Republican vote would be badly split so that none of them would finish in the top two. A tweet from President Donald Trump in support of John Cox, however, may have been exactly what was needed to signal to rank-and-file voters which one of the candidates was viable. Republican voters had no obvious choice, and given that whoever advanced to November seems almost certain to lose, it wasn’t an election worth researching in depth. That’s the perfect environment for which a clear signal can be very effective.

But Democrats have neither a president nor a clear leader who can send that kind of signal. Which makes their success all the more impressive.

The truth is that from clearing the field in key Senate races to avoiding disruptive primary challengers (especially in competitive districts) to sorting through large candidate fields and the special circumstances of California, the Democrats are very much behaving as we would expect a strong party to do. That doesn’t guarantee success in November; it just means that to the extent the party does succeed, it will do so as a party — and it will likely govern as a party, should it get the opportunity.

To a large extent, that’s also true for Republicans, outside the (extremely important!) anomaly in the White House. The Republican Party is dysfunctional, but it’s not weak. No matter what reformers throw at them, we’re just in an era of strong parties.

Jonathan Bernstein is a columnist with Bloomberg News.