From a wikipedia page on Robert Dahl:
"In another landmark book, Democracy and Its Critics (1989), Dahl makes his view about democracy clear. No modern country meets the ideal of democracy, which is as a theoretical utopia. To reach the ideal requires meeting 5 criteria:
Effective Participation - Citizens must have adequate and equal opportunities to form their preference and place questions on the public agenda and express reasons for one outcome over the other.
Voting Equality at the Decisive Stage - Each citizen must be assured his or her judgements will be counted as equal in weights to the judgements of others.
Enlightened Understanding - Citizens must enjoy ample and equal opportunities for discovering and affirming what choice would best serve their interests.
Control of the Agenda - Demos or people must have the opportunity to decide what political matters actually are and what should be brought up for deliberation.
Inclusiveness - Equality must extend to all citizens within the state. Everyone has legitimate stake within the political process.
Instead, he calls politically advanced countries "polyarchies." Polyarchies have elected officials, free and fair elections, inclusive suffrage, rights to run for office, freedom of expression, alternative information and associational autonomy.
Those institutions are a major advance in that they create multiple centers of political power."
The question then is then - what can we do to move closer to the ideal? In Dahl's book How Democratic Is the American Constitution? he seems to say that multi-party democracies are more participatory than two-party democracies.