At the moment the polls closed in three states on Super Tuesday and pundits were cleared to project the winners, two prominent news sites encountered serious performance problems, taking longer than 30 seconds to load web pages. Desktop users looking to ABC News and Fox News for the first indication of voters’ presidential nominees had to wait or, more likely, go somewhere else to see the results.

The issue didn’t last long – less than ten minutes – and didn’t affect all users. Of the tests that Catchpoint ran to gauge the sites’ speed, availability, and reliability roughly half showed normal performance. Still, it was more than enough to create a poor user experience for some, chase viewers to competitors, and impact advertising revenue – especially when it happened again an hour later.

As projections for the next five states’ election results became available at 8pm ET Fox News’ site again become unresponsive for some users. CBS News’ site suffered a nearly identical lag. Once again both sites returned to normal a few minutes later, but frustrated users may have already gone elsewhere by then.

The culprit was the same in both incidents: a common third-party behavioral tracking service that became unreachable. It’s possible that a flood of requests temporarily overwhelmed the service, which recovered quickly – but not until a significant number of users were impacted. This may have seemed familiar to Fox News, which saw third-party objects hamper its web performance during coverage of the New Hampshire primaries.

Whatever the reason, the news sites could have avoided the issue by loading third-party resources asynchronously, skipping past the unresponsive service and delivering the rest of the elements to let the user interact normally with the content. The issue would still have been seen and diagnosed by their monitoring solutions, but their user experience would be unaffected. And their audiences would have been among the first to see Hillary Clinton and Donald Trump staked to big leads on Super Tuesday.

The 2016 presidential election will continue to feature pivotal primaries, increasingly intense public interest, and predictable spikes in website traffic and user requests. Catchpoint will continue to watch popular news sites to see how they perform and whether they learn from issues like these as the race progresses.