Yes, because the idea of democracy is constantly adapting. As we evolve as a culture, we change what we expect. I think America's last presidential election is a good example of the evolution of democracy. Some people tried to buy the election. Interestingly enough, the candidates that spent the most did not necessarily win.
Historians argue whether the American Revolution was democratic in nature. Much recent work suggests that the people who actually fought in it hoped it would be, and indeed many of the state constitutions that emerged in the aftermath of the conflict, especially in Pennsylvania, reflected highly democratic tendencies for the time (allowing almost all white males, and in a few cases, free blacks to vote.) But the aftermath of the Revolution saw a turning away from these principles, as new constitutions were written that were aimed more at preserving property and by extension, political power of elites than anything approaching democracy. Some historians, most notably Gordon Wood, have argued that elites couldn't put the genie back in the bottle, so to speak, and that the Revolution had so eroded traditional patterns of deference and hierarchy that a new democratic order emerged in spite of the efforts of its opponents. Thus, by the 1820s, as pohnpei observes, all white men could vote, and American culture, as well as politics, had become a white man's democracy.
Democracy is the equality of rights and privileges shared among all citizens; a condition in which the common class has equal rights and privileges with the upper class. In respect of these two ideas, democracy has not changed since the Revolution because (1) power in government is still held by Senators who are permitted to vote "their conscience" even when that opposes the will of the people; (2) presidential elections are still held in the hands of the Electoral College; (3) privileges are not shared commonly by all, which is one point being debated today in negotiations on the "fiscal cliff";
Notice that post #2 notes that in the 1820's all "white men" could vote. Yes, this signalled a more inclusive democratic ideal than we previously had, but isn't it ironic that nonwhites and women are still, at that point, not enfranchised. In fact, women will still be denied the vote for about another century.
So our democracy continued to change in important ways, but very, very slowly.
It did not really change from right before the Revolution to right after. But in the next 30 years or so it changed. It came to be more expansive. That is why after the Revolution states generally had property requirements for voting but by the late 1820s all white men could vote.