Disparity in primary vs. caucus results in Texas?

In my precinct primary, Hillary beat Obama by roughly the state average, about 51% to 48%. However at the precinct caucus, Obama won 80% of our delegates. I've spoken to participants of other precinct caucuses and our numbers were similar to those of other precincts, but the popular vote still had Clinton up by a few percentage points. What are some things that could explain this? Perhaps that Hillary typically does well with an older demographic that might not have shown up to the later caucuses? Or might it be that Obama's campaign seemed to get the word out about the caucus than Clinton's?