NEW ORLEANS – Louisiana Senate candidate Charlie Melancon (D) dropped in at a makeshift campaign phone bank in a supporter's law firm in New Orleans Saturday afternoon. After greeting staff and volunteers, he said down to make a few calls himself.

"Is this Shelly? This is Congressman Charlie Melancon, how are you?," he said during one exchange. He asked if the woman had voted. "Thank you so much, I appreciate it," he said, after she told him she had.

The calls didn't all go so smoothly. 

He got a cold response from one gentleman. "That's alright, maybe I can ask you to vote for David VitterDavid Bruce VitterWhere is due process in all the sexual harassment allegations? Not the Senate's job to second-guess Alabama voters The Senate 'ethics' committee is a black hole where allegations die MORE?" he said before hanging up. "I just got a Republican!," he announced to the dozen or so staff and volunteers who braved the rain to help turn out Democratic voters.

Melancon's call sheet was reflective of the logistical problems both major Louisiana parties have identifying their voters. Of the almost three million registered voters in the deep-red state, 1.5 million are on the books as Democrats and about 750,000 are Republicans, according to the secretary of state's office. The rest are affiliated with "other parties."

In reality, thousands of voters who are registered as Democrats are actually Republicans but haven't had to change their party affiliation because up until 2008 Louisiana had an open primary system. That meant a Republican, say, could cast their ballot for a Democratic candidate they supported in a congressional primary, or vice versa. 

Now, under the closed system, only Republicans can vote for GOP primary candidates while Democrats allow unaffiliated voters to cast ballots for their candidates. The need for voters to register by party to vote in their preferred primary should soon cause the registration rolls to better reflect the state's conservative leanings.