Senate impeachment trials are rare in American history, but there are some rules and precedent for how it all works. Reporter Paul Kane answers questions like: Can the rules change by Senate vote? Who collects evidence? And does public opinion matter?

Reporter Mike DeBonis explains the information gathering efforts on the Hill this week. Plus, we dig into whether closed door hearings are unusual for a Congressional investigation, and what the inquiry’s pace suggests about the Democrats’ strategy.

First, Pentagon reporter Dan Lamothe explains the complexities of the Turkey-Syria conflict. Then, political reporter Robert Costa explains how Trump’s decision to withdraw U.S. troops from the border area might be putting his political coalition at risk.

Reporter Shane Harris breaks down how the State Department blocked the U.S. ambassador to the European Union from testifying to Congress Tuesday. If few testimonies actually happen, what does that mean for the impeachment inquiry going forward?

Reporter Aaron Blake explains what makes Trump’s request of China different from that of Ukraine, how federal election law might apply, and where the founders of our country stood on foreign interference in our government.

President Trump’s targeted effort to discredit, and reveal the name of, a government employee raises questions about legal protections for whistleblowers -- and the repercussions for whoever might disclose his or her identity to the public.

Reporter Matt Zapotosky on how this fast-paced news week unfolded, what we learned from documents, transcripts and testimonies, and what happens next now that House Speaker Pelosi has opened a formal impeachment inquiry into the president.

The latest move from the Trump administration threatens to set in motion a massive legal battle and plunge automakers into uncertainty. The Post’s Juliet Eilperin explains how much power a president has over national environmental policy.

Weather editor Andrew Freedman explains how Trump’s inaccurate hurricane tweet led to worrying implications for NOAA and the NWS, and what happens when a president politicizes scientific institutions.

Some of President Trump’s allies described a lost summer, full of controversies and missed opportunities. White House reporter Ashley Parker explains how presidents have strategized in summer, and how Trump’s approach is different.