Yes, political parties do play an important role in U.S. political campaigns and elections. Without political parties, elections and campaigns would not exist.
Political parties distinguish opposing sides of ideas represented by a single candidate for their ideas. For example, the Democrat and Republican parties. The Democrats carry a liberal outlook while the Republicans have a conservative view. A split in ideas or opposing sides creates the need for elections for choosing candidates for the vice-president and president. Campaigns for getting voters to choose sides are done with colorful and extravagant banners and speeches made by the candidate on the radio. Without sides, there would be no elections or campaigns.
Another reason is that political parties help provide money and support for campaigns and elections. Without money, campaigns and elections would never exist. Political parties stand as a whole, and not as one person meaning, groups need to support their members. The group is there for supporting one another and their selected candidate. One single person is unable to have enough sufficient money to support themselves. Without political parties, not only would the existence of campaigns and elections be lost, but it would become hard to control ideas. Since every person carries many different ideals, in order to not cause chaos, groups of people with similar ideas or interests, join together to create a more organized environment for the voters and the parties themselves. Not everyone can win, and there can only be one leader with followers to support him so there exists the need for parties.
Political parties not only play a large role in campaigns and elections, but also politics in general. Political parties are the main event in any political realm.