A key, defining feature of the RAND American Life Panel is that it is a longitudinal panel. You can track public opinion by surveying the same people over time. This allows observation of true changes in public opinion, rather than changes based on who was surveyed randomly. This approach was extremely effective in forecasting the 2012 U.S. presidential election and also in the roll-out of the Affordable Care Act.
And since all previous surveys are available online to researchers, you can link any new data to previous data that has been collected over the years.
Learn more about the methodology and results of several ALP projects: