By Karen Shanton

The New York Senate and Assembly have approved a proposal to join the National Popular Vote (NPV) Interstate Compact. The New York Legislature’s March 25 sign-off on the bill, which next goes to Democratic Governor Andrew Cuomo, follows approval of a similar measure by the Oklahoma Senate in February and Rhode Island’s sign-on to the compact in mid-2013.

These movements on NPV were a (relatively) long time coming in all three states. New York has seen NPV legislation every biennium since the compact was formally introduced in 2006. And Oklahoma and Rhode Island were not far behind. Lawmakers in both states have offered NPV bills every biennium since 2007.

If New York and Oklahoma enact their bills, they will become the 11th and 12th jurisdictions to join the compact and bring the total number of electoral votes pledged to it to 172. The compact, which commits signatories to awarding their electoral votes to the winner of the national popular vote, only goes into effect if jurisdictions with an absolute majority of electoral votes (currently 270) sign on. The addition of New York and Oklahoma would bring it to just under 100 votes shy of that mark.

Of course, though, either effort could yet fall short. Going by track record, passage of NPV in one chamber seems far from a guarantee of enactment. Fourteen states have seen NPV legislation clear one chamber and falter in the other. In some, this has happened more than once. For example, Colorado’s NPV proposal has cleared a single chamber three times, once in the House and twice in the Senate, without achieving passage in both at the same time. Though four of the 14 states ultimately passed NPV in both chambers in the same session, the other 10 have yet to replicate that success.

Unsurprisingly, the odds improve when a bill clears both chambers. Of the nine states where NPV legislation has passed both chambers in the same session (not including New York), all nine have enacted it. However, they didn’t all make it on the first try. In Rhode Island, NPV legislation was passed in 2008 but vetoed by Republican Governor Donald Carcieri. The state saw two more unsuccessful bids to join the compact, in 2009 and 2011, before finally enacting NPV last year. NPV bills were also vetoed in three other states–California (twice), Hawaii and Vermont–before final enactment.

So, Cuomo would not be the first governor to veto NPV legislation. Interestingly, though, he would be the first Democratic governor to do so. Though NPV proposals often have bipartisan backing, all four NPV vetoes to date were handed down by Republican governors. The Hawaii Legislature overrode Republican Governor Linda Lingle’s veto to enact its measure. In the other three states, the bills were re-passed under, and signed by Democratic governors.

Karen Shanton is a legislative studies specialist and ACLS public fellow at NCSL. Email Karen