The Clinton impeachment took place amid the rise of Fox News and the Drudge Report and it felt at the time like a whole new political reality. It was an ugly moment. Larry Flynt, the pornography king, offered a $1 million bounty for dirt on lawmakers’ sex lives, exposing Republicans including the incoming speaker of the House. Mr. Clinton’s foes could bypass the mainstream media filters and pump into circulation wild conspiracy theories and salacious gossip about him through the internet.

But as it turned out, the fragmentation of society and reality was only in its infancy. Today’s impeachment battle occurs in a news and social media environment that rewards the loudest, angriest voices and has separated Americans into their own information silos.

Conspiracy theories are everywhere and conspiracy theorists are in the White House and Congress. Mr. Clinton could go before television cameras, but he had no Twitter to slam out 123 messages in a single day nor a Fox News to hammer home his version of events night after night.

The parties have become even more homogeneous in the last 21 years and the divisions starker. Mr. Trump is the most polarizing president in modern history, playing to racial, ideological and economic rifts rather than seeking to heal them. He has set the tone with relentless attacks and misrepresentations, amplified by conservative and social media. While Mr. Clinton acknowledged wrongdoing, even as he denied breaking the law, Mr. Trump never admits mistakes and forces his allies to defend him without qualification.

The animus Mr. Trump generated among his critics led to talk of impeaching him even before he took office. Speaker Nancy Pelosi and other Democratic leaders came under powerful pressure from their liberal base to abandon their reluctance to pursue impeachment after revelations of the president’s effort to solicit foreign assistance with his domestic political battles.

Some worry that impeachment will now become just one more political weapon. “Whenever one has the president of one party now and the House of the other party I think we’re going to see this more often,” said Representative Steve Chabot, Republican of Ohio and another of the 1998 survivors still on the Judiciary Committee. “And it really is divisive and it really does keep you from focusing on many other things.”