State Senator and Secretary of State candidate Leonidas Raptakis (D, Coventry, East Greenwich, Warwick, West Warwick) has submitted legislation that would insert the following language into state law:

No political party shall prohibit any independent registered voter who has no affiliation with any political party from participating in any political primary.

Here’s his press release, which (curiously) he sent out himself, rather than through the senate’s procedure:

State Senator Lou Raptakis, who recently announced his campaign for Secretary of State, is drafting legislation that would prevent any political party in Rhode Island from holding a closed primary. The Rhode Island Republican Party is considering closing their primary and prohibiting the participation of unaffiliated voters, a voting block which constitutes the largest group of voters in the state.
Raptakis said that no political party in the state should expect taxpayers to pay the bill for a party primary which shuts out 335,288 unaffiliated voters.
“It’s very simple,” said Raptakis. “If a political party wants to turn an open primary election process into an exercise in determining the will of their own members, then that party should not expect the taxpayers of Rhode Island to pay the bill.”
Raptakis added, “The fact that some members of the Rhode Island GOP are seeking to close their primary, would reduce the number of eligible participants in that primary from 408,089 unaffiliated and Republican voters to 72,801 registered Republicans. Why should the state have to pay for a party’s primary election when that party is telling the overwhelming majority of voters that their participation is not wanted?”
While a spokesperson for the Secretary of State suggested that their interpretation of the law was that Republicans could not hold a closed primary, it is expected that if the state GOP votes to bar unaffiliated voters from their primary, the issue will wind up in state court. Raptakis noted that Rhode Island General Laws 17-15-24 establishes that the only people who can be prohibited from voting in a party primary are those who vote in the primary of another party and don’t disaffiliate or those who have designated their affiliation with another party.
“I don’t believe the state’s election law allows for a closed primary, but a judge may rule otherwise,” said Raptakis. “I think we need to make it crystal clear that as long as the state is funding primary elections, it will not allow any political party to significantly limit participation in the electoral process.”

If Raptakis is so confident that a party cannot close its primary, then why the legislation? In other words, why is a closed primary such a threat that it must be “crystal clear”?
One obvious reason might be that Democrats like the easy option of jumping over to control the effectiveness of the other side. The small size of the RIGOP also represents a little bit of an advantage for Republican candidates in a closed primary, because they can campaign to a smaller group of people, avoiding expense and center-stage bloodshed, almost as a community discussion. A third reason could be that Raptakis, himself, is a right-leaning outlier among Democrats and fears that his own party might follow suit, effectively blocking his campaign.
Evidence that the proposed legislation is more political than principled can be found in the fact that the legislation makes no reference to the funding of primaries, however much the senator may stress that rationale.