Slates of presidential electors in all 50 states and the District of Columbia voted on Monday to make Biden’s win official.

President-elect Joe Biden has officially earned over 270 Electoral College votes, formally cementing his victory over President Donald Trump.
Slates of presidential electors in all 50 states and the District of Columbia met to cast their votes on Monday, beginning with Indiana, New Hampshire, Tennessee, and Vermont at 10 a.m. ET.
Biden surpassed 270 votes formally cast for him with California’s votes shortly before 5:30 p.m. ET. He is set to address the nation on Monday night at 7:30 ET.
In the 2020 presidential election, Biden earned 306 Electoral College votes compared with 232 for Trump. Biden flipped five states — Arizona, Georgia, Michigan, Pennsylvania, and Wisconsin — that voted for Trump in 2016. 
The Electoral College votes are usually a little-scrutinized formality that takes place in state capitols in December every four years without much fanfare. But in 2020, the Electoral College voting brings an end to an unprecedented effort by Trump and his allies to subvert and undermine the election results in state and federal courts across the country.
The process looked a little different than normal, with electors social distancing and wearing masks while voting, and Nevada’s electors making history by casting their votes virtually over Zoom.
Still, the day proceeded remarkably smoothly across the nation. With only Hawaii left to vote, there have so far been zero “faithless electors” who cast their votes for a candidate that did not win their state.
Thirty-two states bar presidential electors from defecting and voting for a candidate other than the one they were selected to vote for on behalf of the state, laws that the US Supreme Court ruled to uphold in a July ruling. 
In the nearly six weeks since the presidential election on November 3, Trump and some of his allies have lost dozens of lawsuits directed at throwing out scores of ballots, halting vote counting, delaying certification, and even having the state’s election overturned.
And on Friday evening, the US Supreme Court declined to hear a long-shot challenge brought by the state of Texas against four states Biden won. The suit asked the court to throw out those state’s election results altogether.
The Electoral College formally voting for Biden is likely to close the door on any further litigation of election results. 
After a state’s electors cast their votes, they transmit copies of the certificates of their votes to the National Archives, the president of the Senate (a role fulfilled by the Vice President), the state’s chief election official, and the presiding US District Court judge in the area where the electors meet to cast their votes.
Under the Electoral College system, states are not required to hold popular elections to select their presidential electors, and there is no constitutional right to vote for the president. States have opted to select their electors with popular elections since the 1860s.
Every state except for Maine and Nebraska allocates their electors with a “winner take all” system, in which the candidate that earns the most votes earns all of the state’s Electoral College votes.
Congressional clerks pass the Electoral College certificate from the state of Ohio while unsealing and organizing all the votes from the 50 states in the House of Representatives chamber at the U.S. Capitol January 4, 2013 in Washington, DC.
Chip Somodevilla/Getty Images)
In the Electoral College system, voters are really voting for slates of presidential electors — who are usually loyal party activists or local and state elected officials selected by the state parties — who then vote for president and vice-president. Neither members of Congress nor federal government employees can serve as presidential electors. 
Federal law requires states to appoint their slates of electors on the first Tuesday after the first Monday in November.
Then, on the second Monday after the second Wednesday in December, which falls on December 14 in 2020, the slates of electors are set to meet and formally cast their votes. December 23 is the deadline for electoral college votes to be transmitted to Congress. 
After the next Congress is sworn on January 3, Vice President Mike Pence will preside over a joint session of the new Congress on January 6 to oversee the formal certification of each state’s slates of electors. 
The vice president reads aloud every state’s certificate of their electoral votes in alphabetical order. One member of the US House and one member of the US Senate must both move to contest a given state’s slate of electors, at which point Congress would debate whether to accept the slate. 
Read more: The race for the Republican 2024 presidential nomination is just getting started. Here’s Insider’s rankings of the top 14 likely candidates, from Trump to Pence to Haley and Hogan.
At least one Republican House member, Rep. Mo Brooks of Alabama, is expected to try to challenge a state’s electoral votes in a last-ditch effort to block Biden’s win.
So far, it’s unclear whether or not any Republican Senators will join Brooks in a move to contest a state’s electoral college.
The last time a state’s electoral votes were seriously contested in Congress was after the 2004 election, when Democratic Rep. Stephanie Tubbs Jones and Sen. Barabara Boxer moved to challenge Ohio’s electoral votes after reports of widespread election mismanagement and voter suppression. After a few hours of debate, Congress moved to accept Ohio’s electors.