US House Speaker Nancy Pelosi speaks during her weekly press conference at the US Capitol in Washington, DC, on May 23, 2019. Mandel Ngan | AFP | Getty Images

In the rising congressional impeachment debate, House Speaker Nancy Pelosi occupies the hottest seat. Some think she's burning herself. About three dozen House Democrats have called for impeachment hearings on President Donald Trump, a billionaire's TV ads rip the House for "doing nothing," and legal experts find clear justification in special counsel Robert Mueller's report. Pelosi keeps resisting — variously citing GOP opposition, Trump's ability to exploit the issue, and the need for more investigation before making a decision. "Pelosi's arguments against initiating impeachment are so obviously weak," Susan Hennessey, executive editor of the online journal Lawfare, tweeted. "This is starting to feel more like House Dems actually just don't know what they're doing."

But those seeking to elect a Democratic president and Congress in 2020 feel something different: a deft strategy to temper impeachment fires without extinguishing them. Democratic pollster Celinda Lake says Pelosi has handled impeachment "brilliantly." "She's doing a very good job of moving the caucus to a place that works the best for the most members," adds Democratic strategist Geoff Garin. Buffeted by competing interests, "She's balancing those things as well as anybody could." Even if Pelosi approved, it's unclear impeachment could currently muster the 218 votes needed in the House, much less the 67 required for conviction and removal from office in the Republican-led Senate. The Democratic caucus contains 235 members — 31 representing districts Trump won in 2016. Public opinion explains the challenge. A recent Quinnipiac University poll showed that Americans are opposed to impeachment hearings now by better than 2-to-1. Nor are even rank-and-file Democrats demanding it. In the latest NBC News/Wall Street Journal poll, just 30% of Democrats saw enough evidence to begin impeachment hearings now, and 50% wanted Congress to probe further before deciding. Pelosi's approach matches that sentiment precisely. She has encouraged multiple House committees to keep gathering documents and witness testimony — including testimony from Mueller about his Trump-Russia findings. Her calculations appear at odds with her vow not to seek or avoid Trump's impeachment for political reasons. But Democrats of Pelosi's generation, recalling how Republican zeal in pursuing President Bill Clinton over the Monica Lewinsky scandal in 1998 cost the GOP House seats and Newt Gingrich his speakership, fear their own 2020 backfire. Frustrated younger Democrats see a more complicated history. After the Senate acquitted Clinton of impeachment charges in February 1999, Republicans beat his vice president to capture the White House and kept control of Congress in 2000.