I've read it. And I just read it again. Chief Justice Marshall perfumed the opinion with fine references to noble principles, but when you stand back and look at it....it was still a power grab. Now, I'm not saying that it was an extra-Constitutional power grab. Because the Constitution doesn't prevent power grabs or even overt tyranny. All that it really ensures is that power be collaboratively hared amongst the three branches of government. If the three branches of government decide that power over the citizenry should be increased to unheard of levels, then there is nothing in the Constitution that stops it. Slavery? A-OK! Confiscatory taxes? No problem! Forcing the population to buy into a social or health insurance scheme? Go for it!
Lysander Spooner got it right well over 100 years ago when he noted that "The Constitution has either authorized such a government as we have had or has been powerless to prevent it."