SALEM — Gov. Kate Brown has signed a measure granting Oregon's electoral college votes to whichever presidential candidate wins the national popular vote.

Oregon on Wednesday became the 15th state to make such a pledge as part of the so-called National Popular Vote Interstate Compact. It's an agreement between states to essentially ignore the Electoral College, changing the way the nation elects presidents.

The law doesn't go into effect until enough states join to reach 270 electoral votes. That's the minimum amount needed for a candidate to win the presidency.

With Oregon's 7 electoral votes, the movement is now 74 electoral votes short of that goal. Maine is also considering joining the compact.

Brown says the measure would increase voter turnout and make Oregon "part of the national conversation around presidential elections." She argues it would encourage presidential candidates to campaign in more non-battleground states like Oregon.