Stephen Farnsworth, a political science professor at the University of Mary Washington, said the fact that Mr. Biden isn’t mopping up just about every vote at this point in the primary contests is not a surprise.
“Activists on both sides of the political divide often find themselves frustrated by the barriers to change that exist in national politics,” he said. “What you are seeing with the Democratic primaries in recent weeks is a preference being expressed by some Democratic voters that Biden move in a more liberal direction.”
