Voting under Oath

The South Carolina Democratic Party is requiring that voters declare that they are Democrats in order to vote in Tuesdays’ primary.

Voters who appear at their polling places will be asked to sign an oath swearing that “I consider myself to be a Democrat” before casting their ballots.
If they don�t sign, they can�t vote.
Democrats say they don�t want to keep independents away, but they do hope to deter Republicans from voting in the primary and interfering with the results.
The pledge is legal because the Democratic Party � not the state Election Commission � runs and pays for the presidential primary, said Donna Royson, deputy executive director of the Election Commission. South Carolina requires only that voters declare they have participated in just one party�s primary.
Democrats said the national party has required the pledge since 1984 in South Carolina and other states that don�t require voters to register by party.

Funny, I’ve never registered with a party or taken the Democratic pledge.
Some contend the vow discourages independents from participating in the primary. Former DNC Chair Don Fowler counters:

“We want everybody to come vote as long as it�s done in good faith,” said Don Fowler, a former Democratic National Committee chairman. “I don’t think many Republicans will come. If they want to come and consider themselves a Democrat for the day, they�re welcome.”

If that’s the case, why even have the requirement? It seems silly and will only filter out the more moderate voters who will likely determine the race this November.