At first glance, the new Gallup data showing that 70 percent of Americans view the U.S. healthcare system as having "major problems" or being in a "state of crisis" suggests a remarkable amount of stability on the question.

With all the changes that have taken place in healthcare since 2002 — most notably, the introduction of the prescription drug benefit to Medicare and Obamacare — the number of Americans seeing at least major problems with the healthcare system has been relatively constant. It's reached as low as 65 percent during that time and as high as 73 percent, but always basically within the range of seven in 10 people.

However, looking at the partisan breakdown of the numbers shows that there's been a lot more movement — it's just that Democrats tend to think of the healthcare system as being in shambles when Republican presidents are in charge, and Republicans see it as being in a terrible state when there's a Democratic president.

During the Bush era, the percentage of Democrats identifying major problems with the healthcare system peaked at 84 percent, a number that carried over into the Obama administration. But after Obamacare was passed in 2010, the number collapsed, reaching a low of 59 percent in 2014. However, after two years of President Trump, it's now back at the peak pre-Obamacare level of 84 percent.

Republican opinion has followed a similar pattern. As the Bush administration came to a close and Obamacare was first being debated, 58 percent of Republicans reported significant problems in the healthcare system. By 2016, the final year of Barack Obama's presidency, that number had shot up to 80 percent.

But under Trump, concerns have dissipated. And now just 56 percent of Republicans say there are major problems with the system, the lowest level recorded since 2004, the year former President George W. Bush was re-elected.

Up to a certain point, this makes sense. After all, Obamacare reflected the Democratic vision for healthcare, so it follows that its implementation would make Democrats more optimistic about the system and Republicans less so.

But the changes during the Trump administration are harder to explain logically. Sure, Trump and Republicans have tinkered around the edges, but the law still remains largely intact. It doesn't particularly follow that Democrats should be as worried about the system as they were before the passage of Obamacare, given that objectively the system is much closer now to what they want than it was in 2009. And it doesn't make much sense for Republicans who were so concerned about Obamacare to feel suddenly that the system is just as fine as it was before the law was passed.

So it's more likely the case that perceptions of the healthcare system, as with many other issues, are heavily influenced by whichever party happens to be in power than actual substance.

It's also worth noting that as negative as Americans seem to be on the healthcare system as a whole, around 80 percent have consistently said they are satisfied with their own personal healthcare coverage.