Nevada's Democratic Gov. Steve Sisolak vetoed a bill on Thursday that would have pledged to award the state's 6 electoral votes to the presidential candidate who wins the national popular vote.

Why it matters, via The Nevada Independent's Jon Ralston: Sisolak's move blocks "something broadly popular with Democrats, putting what he believes and the best interests of his state above partisan politics."

Context: The bill would have added Nevada to the National Popular Vote Interstate Compact. That pledge kicks in if states that collectively hold 270 electoral votes sign on, enough to ensure the winner of the national popular vote would win the presidential election.

So far in 2019, Colorado, Delaware and New Mexico have signed onto the initiative, bringing the total to 15 signatories and 189 electoral votes.

The other side: Critics of the national popular vote movement say it could render rural states irrelevant in the presidential selection process, encouraging presidential candidates to opt out of campaigning in those states, per NPR.

Sisolak echoed that sentiment with his veto, saying the compact "could leave a sparsely populated Western state like Nevada with a greatly diminished voice in the outcome of national electoral contests."

Whats next: Oregon and Maine, which collectively hold 11 electoral votes, currently have bills supporting joining the national popular vote pledge winding their way through both statehouses.

Go deeper: Where each 2020 Democrat stands on abolishing the electoral college