Former President Donald Trump said Tuesday he could soon be facing his third criminal indictment of the year. No president or former president has ever been charged with one crime, let alone three, so terms like "historic" and "unprecedented" no longer feel large enough to explain what is going on here.

What we know for sure is that Trump said he's been informed he's a target of the Justice Department's investigation into the January 6, 2021, insurrection and efforts to overturn the 2020 presidential election and that the former president has been invited to appear before the federal grand jury in Washington, DC, that's been hearing evidence related to that investigation.

Read the full report from CNN's Jeremy Herb, Kristen Holmes, Kaitlan Collins, Paula Reid and Katelyn Polantz.

We should wait to see what, if anything, Smith ultimately alleges against Trump or his associates. But what Trump wanted to do to erase his election loss and how he planned to do it has been well documented in the years since.

Here's an attempt to synthesize what CNN has been reporting in recent months along with what the House select committee that investigated January 6 laid out in its hearings and what Trump said publicly in 2020 and 2021. There are strong indications that whatever case Smith could bring would revolve around Trump's public and behind-the-scenes effort to circumvent the Electoral College.

How is the Electoral College supposed to work?

Americans technically vote for electors when they vote for presidential candidates in early November. Electors are real people -- often party activists -- and the electors for the popular-vote winner in each state meet in their statehouses and cast electoral votes in mid-December (December 14 in 2020). Those Electoral College votes are then counted in Congress as the vice president presides on January 6. The new president is sworn in on January 20.

How did Trump try to get in the way?

He was up front with the broad strokes.

Here's a tweet from the morning of January 6, hours before people he inspired stormed the US Capitol to stop the certification of Joe Biden's Electoral College win:

"States want to correct their votes, which they now know were based on irregularities and fraud, plus corrupt process never received legislative approval. All Mike Pence has to do is send them back to the States, AND WE WIN. Do it Mike, this is a time for extreme courage!"

What does that mean?

Much of it is untrue. First, not a single state legislature passed any measures trying to "correct" their votes." In fact, Republican state officials in Georgia and elsewhere rebuffed Trump's efforts to subvert the election process. Second, Trump knew there were no widespread irregularities or fraud because the people who worked for him in the White House and elsewhere in the government have testified they told him so.

The important part is that Trump, in this tweet and elsewhere, suggested there was a plan in place for states to make him president if then Vice President Mike Pence would just reject the real Electoral College votes.

What was going on behind the scenes?

Pressuring local officials. While Trump said plainly and in public what he wanted, it's become clear there was a lot of work being done behind the scenes. He was on the phone with Republican officials in key states pressuring them, as he did in Georgia, to "find" votes for him, or in Arizona, where he talked to the state's then-Gov. Doug Ducey, a Republican, about the 11,000 margin by which Biden won there.

Weaponizing the Justice Department. Trump repeatedly tried to enlist senior Justice Department officials and other federal prosecutors to help him overturn the election. He and his allies unsuccessfully pressed DOJ leaders to publicly announce that the election was "corrupt," and to intervene in key states to derail the election certification process.

Wild plans to intervene. Prosecutors have also focused on a December 18, 2020, Oval Office meeting where Trump advisers like Sidney Powell and retired Gen. Michael Flynn clashed with White House attorneys over wild, ultimately rejected ideas to seize voting machines and dispatch the military into US streets.

The fake electors scheme. Trump's campaign advisers, led by Rudy Giuliani, were coordinating slates of false electors in seven states -- Arizona, Georgia, Michigan, Nevada, New Mexico, Pennsylvania and Wisconsin. Slates of false GOP electors met on December 14, 2020, in shadow certification ceremonies and signed illegitimate certifications that falsely claimed Trump won those seven key states.

They didn't hide it.

"As we speak, today, an alternate slate of electors in the contested states is going to vote and we're going to send those results up to Congress," Trump adviser Stephen Miller said on Fox News on December 14, arguing it would keep Trump's options open in case lawsuits in those states prevailed. The lawsuits all failed, but Trump still had plans for Pence to reject the real Electoral College votes.

December 14 coincidentally, is also the day former Attorney General Bill Barr announced he would resign from the Trump administration.

Read more. CNN's Marshall Cohen has a more in-depth story explaining the fake electors scheme.

How do we know the DOJ grand jury investigation focused on fake electors?

CNN's Casey Gannon and Hannah Rabinowitz have maintained a log of key players we know to have testified before the grand jury or met with prosecutors. Many of the people are known to have been questioned about the fake electors plot. These include top aides to Pence, who ultimately ended the plan by accepting the real Electoral College votes and rejecting Trump's fake ones from the seven states.

What have we learned recently?

CNN reported that Michael McDonald, chairman of the Nevada Republican Party, was one of two alleged Nevada fake electors given limited immunity to testify.

Another recent grand jury witness is Gary Michael Brown, a 2020 Trump campaign Election Day operations official, who had told campaign staff he delivered fake elector votes for Trump to Congress from battleground states. Brown gave the cold shoulder to the House January 6 committee.

Related report: Special counsel trades immunity for fake elector testimony

Key lines from the late June report: Prosecutors have played hardball with some of the witnesses in recent weeks, refusing to grant extensions to grand jury subpoenas for testimony and demanding they comply before the end of this month, sources said. In the situations where prosecutors have given witnesses immunity, the special counsel's office arrived at the courthouse in Washington ready to compel their testimony after the witnesses indicated they would decline to answer questions under the Fifth Amendment, the sources added. At least one other witness has spoken to investigators in the past two weeks outside of the grand jury with an agreement the person would be protected from potential prosecution, another source said.

The fake electors could face scrutiny in their states

The slate of 16 fake electors in Michigan were charged Tuesday by the state attorney general with multiple felonies related to the scheme.

From CNN's report: The group of 16 fake electors from Michigan includes current and former state GOP officials, the Republican National Committee member, a sitting mayor, a school board member and Trump supporters who were the plaintiffs in a frivolous lawsuit that tried to overturn the 2020 results.

There's so much we don't yet know

Smith's team, according to CNN's reporting, has sent subpoenas to local and state officials in all seven of the key states that were targeted by Trump and his allies and where Trump's campaign convened the false electors as part of the effort to subvert the Electoral College.

Trump argues anything he did was included in his protected constitutional right to contest an election. The question is whether Smith decides to argue before a jury that the evidence shows Trump was trying instead to overturn the election and subvert democracy.