“The times, places, and manner of holding elections for Senators and Representatives shall be prescribed in each state by the Legislature thereof; but the Congress may at any time by law make or alter such regulations, except as to the places of choosing Senators.” US Constitution Article 1, Section 4, Clause 1
The States have the authority to determine “times, places, and manner” for holding elections. This includes the timing of primary elections. The State can also set the dates for voter registration before an election, the timing and regulations for petitions to put names on the ballot, and voting poll locations.
Another way that the States regulate the “manner” of elections is by using their power to draw election districts. The Congress does require that the States use a “single-member district scheme”. This means that the State is divided into as many election districts as there are Representatives allotted to that State. As an example, if a State has 12 representatives assigned to it; it would have 12 election districts. This eliminates the Representative being elected “at large” to represent the whole state. Representing a certain election district should increase the Representative’s accountability to their constituents.
The only time that the US Congress has “by law make or alter such regulations” was to set a date for the Federal elections as the Tuesday following the first Monday in November.
The phrase “except as to the places of choosing Senators” is considered a moot point since this referred to the time in history when the State legislatures chose the Senators for each State. This was changed by the 17th Amendment. For more information about the 17th Amendment, please see the post, “Establishment of the US Senate, March 7, 2013.
We the people give the States (with oversight by the federal government) the ability to set the dates and rules for elections.
The benefit to us is that there are laws and rules in place to keep the election process functioning each time it is necessary. Additionally, the individual States have, over the years, retained much of the authority as to how elections are conducted in their State.
References:
Findlay, Bruce Allyn and Findlay, Esther Blair. Your Rugged Constitution. Stanford: Stanford University Press, 1950
US Constitution
Wikipedia, Article One of the United States Constitution