Sen. Charles E. Schumer (D-N.Y.) leaves after the weekly Senate Democratic policy luncheon at the Capitol Nov. 16, 2016, in Washington, D.C. (Alex Wong/Getty Images)

Younger progressives might not remember this, but before the 2016 election changed everything, the 2004 election changed everything. John F. Kerry lost the presidency. Democrats lost seats in the House and Senate. Most humiliating, they lost the seat of their Senate majority leader, Tom Daschle — a debacle that teed things up for a lesser-known Democrat named Harry M. Reid. On DailyKos, then (and maybe in the future) a clearinghouse for progressive activism, this was received as a very bad thing.

“So now the highest ranking Democrat in the country will not even stand up for a woman's right to choose,” one blogger wrote.

“It's clear to me that the current Democrats in power are living by the same strategies they always have without stopping to learn anything,” another wrote.

“We finally get rid of Daschle and now I get Daschle-light?” yet another wrote.

We know what happened next — 12 years of bare-knuckled fights, led by Reid, and eight of them in the majority. To the surprise of many, the soft-spoken Mormon who had once sponsored an anti-“anchor baby” bill brought progressives into the mix as no leader before him. And he mostly won.

I bring this up because the day before Chuck Schumer finally claimed the title of majority leader, protesters occupied his office to demand that the liberal senator from a safely blue state be replaced . . . by a true progressive. They preferred Bernie Sanders, who Schumer quickly brought into the party's rapid response team, just as he was promoting Rep. Keith Ellison for Democratic National Committee chairman. The protesters probably agreed with the Intercept, which branded Schumer “The Worst Possible Democratic Leader at the Worst Possible Time.”

What does any of this mean? First, and most basically, in the rubble of an election loss or the confetti of an election win — really, anytime — it's very hard to predict how a new party leader will perform. Tim Kaine, seen as a smart and safe choice for Barack Obama's first DNC chairman, presided over historic election losses. So did Ken Mehlman (well, not historic, but losses), after riding from the 2004 Bush campaign to the Republican National Committee. John A. Boehner, elected leader in a 2006 compromise, looked like a loser until his party won a majority. In 2002, Nancy Pelosi was widely seen as too liberal to lead the House Democrats to a national victory; four years later, she did so.

Fine, “pundits are wrong” is a lesson we've overlearned in 2016. But why were some of these judgments wrong? In each case, they underestimated that our political system is very, very good to the opposition. In a parliamentary democracy, the losing party is in the wilderness until the next election. In our republic, the minority has a multitude of tricks for gumming up the majority party in Congress; every year, it has multiple chances to seize back states or legislative seats. The total opposition strategy deployed by Mitch McConnell in 2009, who commanded the smallest GOP caucus since the 1970s, ground down much of what President Obama wanted and helped sink the popularity of what passed, like the Affordable Care Act.

In that case, and 12 years ago, the leadership thrived by listening to grass-roots activists and ideological pressure groups. (Are we not supposed to admit that?) In 2005, Reid shook up the Democratic minority (of 45 seats) by adding a war room. His staff then began working, almost immediately, with progressive activists who wanted Democrats to oppose a reelected George W. Bush. The president gave them something to oppose — a hard drive for partial privatization of Social Security.

Since the election, the more pointed worries on the left have not been about Schumer, but about the risk of Democrats finding compromise. Shell-shocked after the election, both Schumer and Pelosi suggested that Democrats could help Republicans pass an infrastructure bill. Jonathan Chait was blunt about the risk: “Charles Schumer and Nancy Pelosi Have a Plan to Make President Trump Popular.”

But Schumer's long history as a Democratic legislator/strategist suggests he was making a longer play. We're talking about the Democrat who warned, 14 months before the 2008 election, that George W. Bush would not get a chance to appoint a new Supreme Court nominee if a vacancy opened. We're talking about a Democrat who watched that quote boomerang into his forehead after Antonin Scalia died. We are talking about the same Democrat who has watched people execute understandable eye-rolls at his terrible summer advice for Hillary Clinton: “For every blue-collar Democrat we lose in western Pennsylvania, we will pick up two moderate Republicans in the suburbs in Philadelphia.”

This Schumer, as the Intercept pointed out, is more comfortable with Wall Street than the base of the Democratic Party now feels comfortable with; he also voted, like Kerry and Reid, for the Iraq War. But our recent experience with party leaders suggests that the base, and the majority-enraging rules of Congress, matter more than the previous political life of the leader. With the exception of infrastructure, there are no ideas likely to emerge from a Paul D. Ryan/Donald Trump brain trust that Schumer will need to support. With the exception of energy policy, there are none that his more vulnerable members are likely to break ranks for. The lesson of Schumer's own career, and the career he has watched Republican leaders have, is that total opposition is the clearest path back to power.