Types of Direct Primaries in the United States

Closed	Semi-Closed	Semi-Open	Open
Party registration required in advance of primary election day	Party registration required, but affiliation may be changed on election day; unaffiliated voters may be allowed to vote in party primaries	Voters must publicly declare their choice of party ballot on primary election day	Voters decide their choice of party ballot in the privacy of the voting booth
Connecticut Delaware Florida Kentucky Maine Nebraska Nevada New Jersey New Mexico New York Oklahoma Pennsylvania South Dakota	Arizona California Colorado Iowa Kansas Maryland Massachusetts New Hampshire North Carolina Oregon Rhode Island Utah West Virginia Wyoming	Alabama Arkansas Georgia Illinois Indiana Mississippi Ohio South Carolina Tennessee Texas Virginia	Hawaii Idaho Michigan Minnesota Missouri Montana North Dakota Vermont Wisconsin

	Blanket		Universal
	Voters may vote in more than one party's primary, but only one primary per office.		All candidates appear together on same ballot. Top two vote-getters, regardless of party, are nominated for general election ballot. Candidates receiving over 50% automatically win office.
	Washington*		Louisiana

* Washington's blanket primary was declared unconstitutional in Federal District Court in 2001 after the U.S. Supreme Court overturned California's blanket primary (California Democratic Party v. Jones, 2000). This ruling was upheld in the 9th Circuit Court of Appeals. The case is currently pending in the U.S. Supreme Court.