In United States politics

Politics of the United States

The United States is a federal constitutional republic, in which the President of the United States , Congress, and judiciary share powers reserved to the national government, and the federal government shares sovereignty with the state governments.The executive branch is headed by the President...

, a sore-loser law is a law which states that the loser in a primary election

Primary election

A primary election is an election in which party members or voters select candidates for a subsequent election. Primary elections are one means by which a political party nominates candidates for the next general election....

 can't then run as an independent

Independent (politician)

In politics, an independent or non-party politician is an individual not affiliated to any political party. Independents may hold a centrist viewpoint between those of major political parties, a viewpoint more extreme than any major party, or they may have a viewpoint based on issues that they do...

 in the general election. These laws do not apply to presidential candidates. Many states accomplish the same requirement by having simultaneous registration dates for the primary and the general election; in fact only the states of Connecticut

Connecticut

Connecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...

, Iowa

Iowa

Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...

, New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 and Vermont

Vermont

Vermont is a state in the New England region of the northeastern United States of America. The state ranks 43rd in land area, , and 45th in total area. Its population according to the 2010 census, 630,337, is the second smallest in the country, larger only than Wyoming. It is the only New England...

don't have either a sore-loser law or simultaneous registration deadlines.