Protesters hold signs and chant during a President Donald J. Trump impeachment rally in downtown Ann Arbor on Tuesday, Dec. 17, 2019. The rally, was one of many held around the U.S. on the eve of President Trump's impeachment vote. (Nicole Hester/Ann Arbor News via AP)

Welcome to 2020. The year of impeachment.

Here are words — a dozen quotations — all spoken by those at the heart of what, no doubt, will shape the rest of the year. Perhaps the rest of our lives. We'll hear these words — and chew on them — over and over in coming months as Congress, the U.S. Senate and voters dissect the importance of the impeachment of President Donald John Trump, the 45th president of the United States, on charges of abuse of power and obstruction of Congress.

1. "I would like you to do us a favor though because our country has been through a lot and Ukraine knows a lot about it."

— President Donald Trump to Ukraine President Volodymyr Zelenskyy, according to a rough transcript of their July 25 phone call. The White House released the four-page summary transcript in September, and it shows that Trump followed it up by asking Zelenskyy to investigate his top 2020 political opponent, Joe Biden, and his son, Hunter, who had been on the board of a Ukraine gas company, Burisma. Trump also wanted Ukraine to find evidence of a long-debunked conspiracy theory that Ukraine, not Russia, hacked a Democratic National Committee server to interfere in our 2016 election.

2. "In the course of my official duties, I have received information from multiple U.S. government officials that the president of the United States is using the power of his office to solicit interference from a foreign country in the 2020 U.S. election."

— The whistleblower complaint, declassified in September.

3. "Read the transcript!"

— President Donald Trump in repeated comments and tweets — most recently this past week.

4. "The actions of the Trump presidency have revealed the dishonorable fact of the president's betrayal of his oath of office, betrayal of our national security and betrayal of the integrity of our elections. ... The president must be held accountable. No one is above the law."

— House Speaker Nancy Pelosi, D-California, announcing in September that she supported an impeachment inquiry into Trump and Ukraine.

5. "As I said on the phone, I think it's crazy to withhold security assistance for help with a political campaign."

— William B. Taylor Jr., the top U.S. diplomat to Ukraine, in a Sept. 9 text message to Ambassador to the European Union Gordon Sondland, ambassador to the European Union and whom Trump tasked with overseeing the Ukraine matter. Taylor's text, released in early October, was the first concrete proof that officials believed there to be a potentially corrupt quid pro quo between the Trump administration and Ukraine.

6. "Did he [President Trump] also mention to me, in the past, that the corruption related to the DNC server?Absolutely, no question about that. But that's it. And that's why we held up the money. ... I have news for everybody: Get over it. There's going to be political influence in foreign policy."

— Acting White House chief of staff Mick Mulvaney, in an October White House news briefing, confirming there was a quid pro quo with Ukraine involving military aid in exchange for Ukraine launching Trump's preferred investigations. Mulvaney later recanted his admission.

7. "I know that members of this Committee have frequently framed these complicated issues in the form of a simple question: Was there a 'quid pro quo?' As I testified previously, with regard to the requested White House call and White House meeting, the answer is yes. By the end of August, my belief was that if Ukraine did something to demonstrate a serious intention to fight corruption, specifically addressing Burisma and 2016 server, then the hold on military aid would be lifted. ... Everyone was in the loop."

— Gordon Sondland, Trump donor, ambassador to the EU and member of "the three amigos" tasked to work with Rudy Giuliani by Trump's Chief of Staff Mick Mulvaney and Secretary of State Mike Pompeo to deal with Ukraine's new president and administration. Sondland made these comments in the November public impeachment hearings.

8. "Congressman, because this is America. This is the country I have served and defended, that all of my brothers have served. And here, right matters."

— Lt. Col. Alexander Vindman, responding on Nov. 19 to a committee question on why Vindman told his father not to worry about consequences for his testimony that he personally heard our president "demand a foreign government investigate a U.S. citizen and political opponent" during Trump's July 25 phone call with the new Ukrainian president.

9. "He solicited foreign interference before, he is doing it now, and he will do it again. The president is the smoking gun."

— Rep. Pramila Jayapal, D-Washington, during the House impeachment debate.

10. "What we are doing here today is not only patriotic, it is uniquely American. America is a story of ordinary people confronting abuses of power with a steadfast pursuit of justice."

— Rep. Ayanna Pressley, D-Massachusetts, during the House impeachment debate

11. "Sadly, but with confidence and humility, with allegiance to our founders and a heart full of love for America, today I am asking our chairmen to proceed with articles of impeachment. The facts are uncontested. ... Our democracy is what is at stake. The president leaves us no choice but to act because he is trying to corrupt, once again, the election for his own benefit."

— House Speaker Nancy Pelosi on Dec. 5.