Are you surprised it’s gotten this far?

Natasha Bertrand, national security correspondent: It was only a matter of time before we got here—the number of Democrats calling for an impeachment inquiry was steadily rising, and Trump’s call with the president of Ukraine was just the tipping point — and the smoking gun — they needed to move forward. The fact that the White House released a record of the call only appears to have helped the Democrats make their case, contrary to what Trump seemed to hope it would do: reassure everyone that the call was “perfect” and “legal.”

Kyle Cheney, Congress reporter: I'll take the easy way out: yes and no. Hollywood would reject the script for this scenario as too far-fetched, so there's no way anyone could have predicted that Trump would lean on Ukraine for assistance in taking down a political rival -- a day after special counsel Robert Mueller testified about the perils of election interference by foreign powers. But there's also no way any honest observer of Washington couldn't envision Trump finding a way to self-sabotage so theatrically that he'd be embroiled in an impeachment process for something entirely unforeseeable a few weeks ago.

Andrew Desiderio, Congress reporter: Pro-impeachment lawmakers have told us for months that Trump would eventually “self-impeach” as he seeks revenge against his political enemies for their pursuit of the Mueller investigation. And Speaker Nancy Pelosi’s formal embrace of impeachment proceedings was a vindication of sorts for them. But if you had told me two weeks ago that the number of House members supporting an impeachment inquiry would balloon as much as it has, I would’ve said you were crazy. The impeachment effort was practically on life support as Democrats largely failed to sustain momentum from the Mueller report. Only a totally separate, unrelated scandal could ignite the impeachment fervor to the point of no return, I told myself. And here we are.

Josh Gerstein, legal affairs contributor: I’m not terribly surprised because Trump never seems to have viewed any of the actions that led to the Mueller probe -- either the original pussyfooting with Russia during the 2016 campaign nor the episodes of potential obstruction of justice that follow -- as any sort of cautionary tale or even a line to steer clear of. It seems like all those times people asked him if he’d accept help from a foreign government and he refused to rule it out, we were supposed to take him both literally and seriously. And that’s why we’re here.

Darren Samuelsohn, White House reporter: Not really. I wrote a story in April 2016 – before Trump was even the nominee – that surveyed this very scenario with the use of my very own flux capacitor. Then, once the Democrats won control of the House in 2018 this seemed to be the logical outcome of the aggressive oversight that Nancy Pelosi & Co. had promised would happen. While we didn’t know when Robert Mueller’s probe would be finished, or what it would say, many of the details were out there that Trump was in trouble for obstruction of justice. I will admit though that I didn’t anticipate the Ukraine curveball.

Let’s talk logistics: How many articles of impeachment do you think the House will write? And how long will impeachment proceedings last?

Natasha Bertrand: I’ll leave this to my colleagues who spend all day reporting on the Hill, but my sense is that while Pelosi would prefer impeachment articles to be short and easy for the public to understand, presenting a consistent pattern of misconduct by the president may be more effective — and more convincing in the annals of history.

Kyle Cheney: The best information we hear from sources is two articles. One would focus on the whistleblower complaint and Trump's efforts to solicit foreign aid in the 2020 election. The other would be an all-encompassing "obstruction of Congress" article in which the myriad Trump investigations led by six House committees could present their best evidence that Trump stonewalled them with unprecedented intensity. The Judiciary Committee has been blocked by the White House from interviewing Mueller's central witnesses; the Oversight Committee faced roadblocks to investigating Trump's handling of the U.S. Census; the Ways and Means Committees is fighting in court for Trump's tax returns; and several other investigations have been ground to a halt by Trump's resistance.

Andrew Desiderio: Some House Democrats would like to see dozens of articles of impeachment against the president — ones that cover everything from Ukraine to Mueller to emoluments and everything in between. But as Kyle said, and as we reported on Friday , Democrats are likely to pursue only those two. It really comes down to whether the House intelligence committee can get its hands on the intelligence inspector general’s report, which presumably includes information that corroborates the whistleblower complaint. If they don’t get the report, it could take longer for the committee to interview witnesses and request documents that it doesn’t already have. The second factor is, of course, the political calendar. Most Democrats acknowledge that it wouldn’t be prudent to be conducting an impeachment proceeding well into 2020.

Josh Gerstein: Before the Ukraine news broke, many Democrats felt obligated to press forward with an impeachment inquiry and some sort of vote on the allegations Mueller investigated. For that reason, I think the articles the House ultimately votes on will have to encompass more than just Ukraine. I’d be surprised if the more liberal members are willing to leave it at just Ukraine and obstruction of Congress and ignore things like Trump’s alleged effort to get White House Counsel Don McGahn to lie about attempts to fire Mueller, but perhaps they could argue they couldn’t clearly establish the facts because of Trump’s stonewalling.

Darren Samuelsohn: I can see why Democrats would want to keep this short and sweet, focused on one issue like the Ukraine and leave behind topics like Mueller and Trump’s business dealings. Then they can get back to their 2020 nomination fight and let Trump be Trump, potentially injecting more impeachment fodder into the mix that they can always come back to later on if things get out of hand or in a second term.

What are the biggest unknowns — and what do you want to know?

Natasha Bertrand: Has Trump similarly pressured other foreign leaders for political favors? Consistent with the whistleblower’s complaint, our reporting indicates that the transcript of the Ukraine call is not the only one the White House “locked down” in NSC’s codeword system. Additionally, we now know certain State Department officials, including special envoy Kurt Volker and U.S. ambassador to the E.U. Gordon Sondland, were involved in facilitating this backchannel—how much did Secretary of State Mike Pompeo know, and did he sign off on it?

Kyle Cheney: What did Trump say to Russian President Vladimir Putin in a phone call a week after he spoke to Ukrainian President Volodomyr Zelensky? The Kremlin revealed only that the two discussed wildfires in Siberia, but the call came just as Trump had withheld military aid from Ukraine and pressed Zelensky to investigate Biden. Soon after the call, Trump began advocating for Russia to rejoin the G7.

Andrew Desiderio: The biggest unknowns at this point center around the corroborating documents and witness testimony that led the intelligence community’s inspector general to conclude that the whistleblower complaint was urgent and credible. The complaint mentions how White House officials were “deeply disturbed” by Trump’s conduct, and that others sought to “lock down” information about the president’s interactions with Zelensky. Democrats will seek to interview those individuals, if they didn’t already speak to the inspector general, to learn more about the president’s push to pressure Zelensky to investigate Biden. Additionally, it remains an open question whether Trump froze military aid to Ukraine in order to gain leverage over Zelensky. As of now, there is smoke, but no fire.

Josh Gerstein: I’d like to know more about how other top U.S. government officials responded to Trump’s effort to pressure Ukraine to investigate Biden. The decision to withhold aid to Ukraine clearly triggered debate and concern within the administration. The July conversation with Zelensky even more so. There are already hints that officials at the U.S. Embassy in Kyiv were drawn into the effort, along with figures like the U.S. Special Envoy to Ukraine, Kurt Volker, who resigned Friday . On the flipside, the whistleblower complaint says some officials raised concerns about the Trump strategy made plain in the call. Who voiced those worries? Where were the complaints directed? Did no one take any action other than the whistleblower?

Darren Samuelsohn: It’ll be interesting to see what Democrats extract from the Trump administration about the role of the president’s aides and advisers. This investigation has the potential to snare any number of top people from the administration, including Vice President Mike Pence, Attorney General Bill Barr and Rudy Giuliani. Each one is likely to face subpoenas to testify, and each is likely given the president’s past rules of engagement to put up a fight. That could mean a digression into the courts, which I don’t think the Democrats want given they’re already fighting for the Mueller grand jury materials and Don McGahn’s testimony in that very same venue. But if they do force it and win, then things could get really interesting and put to the test just how loyal these aides are to Trump.

The adage is that impeachment is all about politics. Politically, who is most at risk here?

Natasha Bertrand: One big risk is that Democrats don’t make a convincing case to the American people, simply by being unorganized and appearing weak in the face of an administration that, to date, has been consistently willing to ignore Congressional requests and demands. Nancy Pelosi admonished House Judiciary Democrats, for example, for not holding Trump pal Cory Lewandowski in contempt “right then and there” for his combative performance in an open hearing earlier this month. Critics have also questioned why the Democrats aren’t doing more to try to enforce subpoenas to hostile witnesses, like using their power of inherent contempt.

Kyle Cheney: The conventional wisdom says Democrats could be punished for overreaching -- but conventional wisdom is almost certainly wrong. The mix of an impeachment process with an election year has never occurred in American politics, so its effects are virtually unknowable. Trump is historically unpopular but voters have also been slow to warm to calls for impeachment. In a Washington news cycle in which one week's controversies are the next week's ancient history, there's not even a guarantee that voters would be thinking much about impeachment by the time they pull the lever -- either in the primary or the general.

Andrew Desiderio: I’m going to echo Kyle with an addendum: Conventional wisdom is almost certainly wrong in the era of Donald Trump. Early on, many Democrats had resisted impeachment because they thought it was bad politics, especially because of unlikely action in the Senate and the divisive nature of the process itself — not to mention, Trump using it as a foil as he campaigns for re-election. But the Ukraine scandal has changed everything about the political calculations. Yes, Pelosi is taking a risk by embracing impeachment proceedings. But she also seems to firmly believe that these allegations — that the president sought to extort a foreign leader to interfere in the 2020 election on his behalf — are so beyond the pale that public support for impeachment will only rise.

Josh Gerstein: Having cut my teeth on the Clinton impeachment, I think there is a key lesson to be learned: The Clinton White House saw the key to staying in good graces with voters was to look like you’re doing your day job. You can get away with a lot if it looks like you’re on the ball. This is really the political challenge for the Democrats: pushing impeachment without allowing it to be all consuming. One particular problem is that impeachment is such a riveting prospect for journalists that we’ll make a huge deal of that and may ratchet back coverage of other things, like policy proposals from Democratic presidential candidates. Perhaps it’s actually a good thing for the Dems that McConnell is almost certain to smother whatever articles of impeachment reach him, allowing the Dems to say they did their duty but not linger on the topic too long into 2020.

Darren Samuelsohn: I don’t buy into impeachment being a weight on the impeaching party in the next election. The evidence I keep hearing cited is 1998, when Newt Gingrich’s Republicans lost seats they hoped to win while preparing to take down Bill Clinton. But that was a midterm election, not a presidential campaign. Plus, George W. Bush won two years later not just because of hanging chads and Al Gore’s stiffness. He promised to “restore honor and dignity” to the White House. So, he made the issues around Clinton’s behavior leading up to his impeachment into a winner. Last thing I’ll say on 1998: It was more than 20 years ago. A lifetime ago in politics, and totally different era before Trump broke all the rules and when twitter was just a funny word.

Impeachment doesn’t happen around here very often. What are you doing to get ready for all this?

Natasha Bertrand: Re-listening to Slate’s Slow Burn podcasts and preparing for the president to become more combative than we’ve ever seen him. An impeachment inquiry, combined with an election year, mixed in with Trump again encouraging foreign election interference? Things are going to get very ugly.

Kyle Cheney: Reading the unsexiest texts possible: Congressional Research Service reports about impeachment process and precedents. There's no true guide to impeachment because each one in American history has been wildly different and arisen amid different circumstances and political climates. But knowing what levers lawmakers have to pull and what processes have guided these rare events in the past will the best harbinger of what's to come.

Andrew Desiderio: For those of us who spend our working days on Capitol Hill talking to lawmakers and aides for hours on end, this is the type of story that we live for. But it’s also a trying time for the country. I don’t think anyone — no matter one’s political affiliation — is truly happy about what we are about to embark on. It’s important for all of us to put that into perspective.

Josh Gerstein: I’m having four gold stripes sewn onto each sleeve of my best suit. On a more serious note, I’m trying to figure out whether there are any hints in the history of impeachment that could allow troublemakers to try to force a trial of Trump in the Senate, perhaps through court action. Seems like someone will try, even if it’s a longshot.

Darren Samuelsohn: I’ve been nerding out on impeachment for a while and would recommend several things. Bob Woodward’s “Shadow” is a great read on presidential scandal and covers all the Clinton stuff well. If you want to learn about the Senate trials of Andrew Johnson and Samuel Chase, the George Washington-appointed Supreme Court justice who was the second Judge to ever be impeached by the House, go find an old musty copy of “Grand Inquests” by William Rehnquist. He published it seven years before he’d end up presiding over the Clinton impeachment trial. And don’t forget the Hillary Clinton zombie memo — definitely worth a click to see why this nearly 50-year old Watergate report written by a team that included the future first lady still matters.