Here is the first of a two part Gallup study of Venezuela. What it shows is an increasing sense that the economy is getting worse and that in general Venezuelans feel they are becoming worse off. This suggests that the protests stem in large part from these feelings.
This is interesting, though it's important to keep two things in mind. First, even under Hugo Chávez these indicators bounced around. So, for example, on the economy:
After 2007 confidence took a nosedive but the government didn't fall apart. That spike at the end, though, is pretty dramatic, suggesting a correlation with Chávez's death and Maduro taking over. It'll be critical to see whether the trend continues or there is more bouncing.
Second, they say nothing about political preferences. The opposition seems to believe that dissatisfaction with the economy translates into support for the opposition, or at least for Maduro's departure. But that's not obvious at all. It's up to Maduro to implement policies that reduce crime and inflation, etc., which would stabilize the situation considerably.
These numbers, though, are indicative of the fact that even if the protests peter out in the next few weeks, the underlying causes for them must be addressed or political conflict will return. If the dissatisfaction continues, then his internal position will weaken. It's hard to see the opposition winning, but easier to see an internal push for a new president if conditions worsen.