Is the filibuster undemocratic?

The filibuster, an abuse of a Senate rule intended to allow the minority to have its say by requiring 60 votes to end debate, has increasingly been used by the minority, whether Republicans or Democrats, to block legislation and appointments favored by the majority. The result is either gridlock, or initiatives watered down and laden with pork to buy the votes of fence sitters. It also makes it hard for the public to gauge the effectiveness of a party's policies. Should we have faith in the wisdom of democracy and one man, one vote, or should we continue to allow the party that lost at the polls to block legislation?