The hits just kept on coming last week — and viewers just kept on tuning into MSNBC. After 21 years of chasing Fox News, it finally scored its first ratings win last week, both in total viewers and in the key 25-54 age demo. Fox came in second for prime time overall, but dropped to third in the demo for the first time in almost two decades:

MSNBC finished first in the key 25-54 demographic and in total viewers against its cable news rivals last week for the first time in its 21-year existence, according to Nielsen Research.

Overall, MSNBC finished second in all of basic cable, only falling to TNT, which aired several NBA playoff games.

Fox News finished third in primetime for the first time in nearly 17 years.

Last week might have been anomalous, especially in terms of content. Every afternoon last week had some breaking story that hammered Donald Trump and/or his administration, some more damaging than others. The natural implications of those stories might have driven prime-time commentary viewers to the network that has defined itself as the center of the Trump opposition, or to CNN and its perceived middle-road approach, rather than the network which has defined itself as Trump’s apologists. If that’s the case, then a smoother week might produce a return to previous form, and the normal Fox domination of prime time in both the overall and the key demo.

On the other hand, the status quo has long gone from Fox News. A year ago, Fox dominated with Bill O’Reilly, Megyn Kelly, and Sean Hannity. Only Hannity remains, and last week he spent a good deal of his time avoiding the daily bombshells about Trump to focus on unsubstantiated theories about the unsolved murder of a DNC staffer from ten months ago. If viewers wanted to hear more about what was happening in real time, they had to go elsewhere. The network has also gone through some serious scandals that have disrupted their prime-time schedule, and it may well be that their audience is now looking at other options, at least for a while.

The other longer-term problem might be that viewers’ passions run toward opposition of the current administration, regardless of who it is. MSNBC serves up anti-Trump commentary by the ton, while Fox has mainly stuck to the pro-Trump approach to story and guest selection. That didn’t bother Fox when George W. Bush was president, but those were also the halcyon days for MSNBC and its prime-time anchor at the time, Keith Olbermann. Fox’s tone during those years was arguably less pro-Bush then than it is pro-Trump now, especially during the second term as conservatives grew more frustrated with the administration, which might hold some lessons for Fox now.

Rachel Maddow also suspects that opposition might be MSNBC’s biggest asset:

Maddow said her show hasn’t changed its approach to the news, but viewers’ appetite for political coverage has changed since President Trump’s inauguration.

“I do cable news in kind of a weird way. We haven’t changed how we do the show at all. It just seems like more people want that now,” she said.

Maddow has held MSNBC’s 9 p.m. timeslot since premiering in 2008, facing off for most of that time with Fox’s “The O’Reilly Factor,” the longtime top-rated cable news show. Bill O’Reilly was ousted last month amid reports of multiple sexual harassment claims, replaced in the timeslot by Tucker Carlson.

In recent weeks, Maddow’s show surpassed Fox News overall and within in the key 25- to 54-year-old demographic.

The bottom line may be that it’s unrealistic to expect a conservative network to dominate cable in a (putatively) conservative single-party government, perhaps especially when the perception is that the network at times offers three different flavors of Trump apologetics night after night. If and when the news cycle calms down, we may get a clearer answer on that, but for one week at least, it’s Fox and not MSNBC that has to wonder whether it needs more changes in its prime time.