Most certainly history contradicts the professor's assertions. Democracy is almost always imposed, and the so-called Marxist growth of democracy is not feasible in light of the fact that non-democratic governments will always resist democratization to the hilt. His views are idealistic and don't take into account the rigid and forceful nature of oligarchies and autocracies.
If democracies are not imposed from without, they must be imposed from within. The United States revolutionary war was promoted, fought, and won by only a third of the inhabitants of the 13 original colonies. The other two thirds were either ambivalent, or opposed to breaking away from England. And when it came time to set up a government a fair number argued for and wanted to establish a new monarchy, or oligarchy in deference to the system they had just broken away from.
It is however true that the institutions and cultural hooks that support a democracy must be nurtured and supported from within, with growth in confidence and belief in the systems growing over time. But without the initial imposition of democratic institutions from within or without, the necessary environment for the growth of confidence in a democratic government cannot exist.
We've seen where liberal ideas on the growth of democracies have led us, with the collapse of the third world's democratic governments, and the rise of autocratic governments in the third world. The premature termination of colonial rule led directly to the weak democratic institutions that eventually collapsed or gave way to anarchy, thus paving the way for autocratic governments. In the decades following WWII the proper method of decolonization should've been slow and based on constant monitoring of the local governmental institutions for corruption and effectiveness. Beginning with the handing over of local governments, and the slow transition of the national governments to local rule. Instead we had a haphazard, happy go lucky divestiture of territory to inadequately supported, highly corruptible post-colonial governments, which has led to the rise of Islamic radicalism as a substitute for law and order in the lawless regions of Asia and Africa.
We are observing the results of bad, liberal/socialist policies and not the results of the European crusades.
True, but there are a few very important points about the U.S. experience that are often overlooked.
1. The United States had a frontier that was largely unsettled and was subject to competing claims from different colonial powers thousands of miles away. As a result, people were far more able to "move away" than they are now.
2. The post-Revolution (and pre-U.S.) period in North America saw a period that was something akin to modern "ethnic cleansing," as British loyalists were basically chased out of their homes and farms and forced to move back to England, to Canada, or out onto the frontier. The United States would have failed in its infancy if George Washington had stood up in the 1780s, suggested that "British tyranny is a religion of peace," and insisted on including hard-core British loyalists in the Continental Congress.