The Constitution does not say anything about political parties--partly because they were a new phenomenon, and partly because the Constitution of 1787 was a brief and general program for setting up a government and left it to future legislatures,state and federal, to regulate voting and legislative procedure. But the authors of the Constitution did think about and prepare for what they feared would be "improper factions"--broad-based political factions based on selfish or improper motives. Your teacher was probably repeating a common misconception, though, which derives from a misunderstanding or just simple dislike of James Madison's argument in The Federalist, especially number 10: "The Union as a Check on Domestic Faction and Insurrection," in which Madison expresses his fears of demagogues and democracy. As you can see for yourself, Madison expected political parties--"factions"--based on special interests, but hoped that in a large and varied federal system they would cancel each other out, and legislators would be obliged to act on shared interests. Safeguards like the Electoral College were built into the Constitution to avoid the "chaos" of factional strife, and were moderately successful for a time, until Andrew Jackson formed the first broadly-based grass-roots party. Congress and the United States Supreme Court have filled in the constitutional blanks concerning political parties, seeking to regulate them, most recently (and unsuccessfully) with regard to the power of money.