Donald Trump just cancelled his rally in Chicago due to "security concerns." CNN reports:

Donald Trump's campaign rally in Chicago on Friday was postponed for safety reasons.

The announcement, which came amid large protests both inside and outside the event at The University of Illinois, comes amid heightened concerns about violence at the GOP front-runner's rallies and four days before Illinois holds its Republican primary.

Hundreds of demonstrators packed into an arena, breaking out into protest even before Trump had showed up. At least five sections in the arena were filled with protesters.

These badasses got inside the event. Here they are shouting: "We stopped Trump! We stopped Trump!"

Here's a CNN anchor making reference to "scuffles" and an inadequate number of law enforcement personnel to deal with them:

What can we conclude from this?