What has contributed to the decline of political parties?
No one wants to have a complicated system. The less political parties there are, the easier it is to vote for a candidate.
What factors contributed to the development of political parties in the united States during the 1790s?
The big four historical political parties are: The Socialist Party, the Social Democratic Party, the People's Party and the Communist Party. Only these four parties survived since (or earlier) the Revolution. Other major parties come and go too fast; since 2000 emerged another party, the Left Bloc, with significant results, though it's been in decline in recent years.
The Canadian political parties differ from those of parties in other political systems in that in Canada the parties at the federal level are only loosely connected to the political parties at the provincial level. In most other countries the political parties at the federal are very tightly associated with those at the lower levels.