In the New Hampshire primary, unaffiliated voters helped power Mr. McCain to a 19-point victory over Mr. Bush, and kept Mr. Bradley close enough to Mr. Gore to remain in the race.
She initially had a big lead in so-called superdelegates (Democratic Party officials allocated votes at the convention that were unaffiliated with state primary results), but, with Obama winning more states and actual delegates, many peeled away from her and went to Obama.
He said he would throw his support behind Elrich as the Democratic nominee and would not back council member Nancy Floreen, a longtime Democrat who changed her registration to unaffiliated after the primary and is planning to run for county executive as an independent.
The only polling of the first primary where unaffiliated voters matter came from the University of New Hampshire last month; Trump was preferred by 68percentt of Republican voters, over a field of Weld and the not-yet (and maybe not ever) declared John Kasich, the Ohio governor whose 2016 campaign carried just one state — his own — over Trump's.
Mr. MacKay noted that in 1986 the United States Supreme Court backed a similar move by the Republican Party of Connecticut to open its primaries to unaffiliated voters.
Sanders advocated for same-day voter registration and said the Democratic Party should switch to a universal system of open primaries, so unaffiliated voters can participate in choosing its nominee.
Weld has said that his campaign will focus on accruing delegates in the 20 primary contests where unaffiliated voters (those not registered with either party) can cross over.
The CPD is charged with organizing the four "real" debates leading up to this November's election (it is unaffiliated with the dozens of primary debates we've seen over the last 18 months).
More than 250,000 West Virginia primary voters were unaffiliated, according to state data.
It's the first time Sanders has won a primary closed to unaffiliated voters. .
Richard Schrader, a Democratic political consultant who has studied the issue, said unaffiliated voters who participate in primaries in the states that permit it rarely enroll in any party in large numbers.
