If a new bill passes through the legislature, Pennsylvania may soon join 11 other jurisdictions throughout the country committed to upholding the popular vote in presidential elections.

State Sen. Daylin Leach, a Democrat representing Delaware and Montgomery Counties, announced Thursday he will introduce legislation that could result in Pennsylvania joining the National Popular Vote Compact — a system that favors the popular vote winner in a presidential race.

The compact would create an agreement between states to commit their electoral votes to the presidential candidate with the most popular votes. Currently, the District of Columbia and 10 states — including California, New York and New Jersey — have passed the legislation into law.

Under the current system, the presidential election is determined not by the popular vote — the number of individual voters who cast their ballot for each candidate — but by a group of 538 electors who make up the electoral college. Each jurisdiction, including all 50 states and the District of Columbia, has three or more electors based on its population. Pennsylvania has 20 electoral votes and therefore 20 electors.

Each jurisdiction’s electors typically vote in accordance with the popular vote of their state, but they are not required to. Electors can change their minds and vote in opposition to the popular vote. Electors who do this are derogatorily called “faithless electors.”

Since the electoral college was created in 1787, there have been a total of 157 faithless electors. The most recent was in the 2004 presidential election, when an anonymous Minnesota elector cast a presidential vote for Democratic candidate John Kerry’s running mate, vice presidential candidate John Edwards.

This year, the electors are casting their votes Dec. 19, and are expected to nominate Donald Trump, who lost the popular vote.

The process of electing individuals to elect the president has long been a source of contention, leading to some — including President-elect Trump, before he was running for office — to call for a transition to a simple popular vote system.

The compact will take effect if it reaches support from jurisdictions totaling 270 electoral votes. The currently committed jurisdictions amount to 165 electoral votes, and Pennsylvania’s membership would add an additional 20 to that number.

According to the release, the division of electoral college votes gives precedence to residents of certain states, since electoral votes are awarded based on population. This means that voting residents in less populous states have more influence over their electoral votes than do voting residents in more populous states, according to the release. For instance, a vote from one Wyoming-resident voter has twice as much influence as a vote from one.

Pennsylvania-resident voter, according to the release. This is a primary reason for the formation of the National Popular Vote Compact, to give equal weight to each citizen’s vote.

In the current electoral college system, a presidential candidate is required to earn 270 electoral votes out of the total 538 in order to win the election.

During the 2016 presidential election, Trump won 306 electoral votes, while Democratic candidate Hillary Clinton won 232 votes. Clinton won the popular vote with 48.1 percent, compared to Trump’s 46.4 percent win of the popular vote.

Because the electors have not cast their official votes, some are petitioning for electors to become “faithless electors” and vote against their states’ popular votes in the hopes of disrupting the results of the November election and electing Clinton over Trump.

A petition on Change.org for electors to vote in opposition to the popular vote has reached over 4.6 million signatures as of Dec. 1.

In cases like this year’s election, the results of the electoral college vote are in direct opposition to the outcome of the popular vote. Although Trump won the electoral college majority, Clinton won the popular vote. In Pennsylvania, a key battleground state in this year’s election, Trump won the 20 electoral votes by a margin of 1.1 points in the popular vote, according to the New York Times’ report.

“In the heart of every American you’ll find an instinctive commitment to the principle of one person, one vote,” Leach said in the release. “Despite that, our country elects its leader using a convoluted and unfair process that values the votes of some over the votes of others. It’s time for Pennsylvania to do the right thing, the fair thing, the democratic thing.”