This article is part of The Week's 20th anniversary section, looking back at how the world has changed since our first issue was published in April 2001.

Twenty years ago this month, I was in the final weeks of a short stint working as a speechwriter for New York Mayor Rudy Giuliani. One day, while toiling on one of the low-profile speeches for which I — the new guy on the communications team — was usually responsible, my boss (John Avlon, now a senior political analyst and anchor at CNN) strolled past my cubicle to see me doing some online research using what I thought was the best option available: the Alta Vista search engine.

"Oh man, you've gotta try Google," Avlon said. "It's way better than what you're using. It doesn't really search the web. It uses some crazy algorithm to search for what other people are searching for. I don't really get it, but it's incredible."

I don't really get it, but it's incredible.

So it was. And so it still is today — something like an interactive, instantaneous card catalogue for a library containing the sum total of human knowledge and creativity. That's an exaggeration, of course. Not literally everything is freely available online. But enough of it is that the prospect of trying to navigate that information without the help of a great search engine feels a little like setting out to find a handful of needles in a haystack the size of Mt. Everest. Simply beyond imagining. To that extent, Google makes online life possible.

Facebook was incredible, too, the first time I tried it a few years later. The website was founded in early 2004. I finally joined it four years later. I used to spend far more time on it than I do today, but I remain connected with five decades' worth of friends, acquaintances, colleagues, and family members from around the country and the world through its interface, and I regularly scroll through videos posted by my favorite bands on their fan pages. Sometimes I even post my columns on the platform and end up having conversations or fighting with some of my 700 or so "friends" who see my articles in their news feeds.

Twitter seemed like a frivolous waste of time the first time I saw it in the years following its launch in 2006. It reminded me of Facebook but with an absurdly tiny word limit. I finally opened an account in January 2012 because my colleagues at Newsweek and The Daily Beast spent a lot of time there. It took me a couple of years to get hooked, but now I work all day with Tweetdeck open in the background on my laptop so I can pop in to see what people are fighting or gossiping about throughout the day. It's a 21st-century version of a teletype machine spewing news and rumors and pointless bile at my brain 24/7. Checking Twitter is the last thing I do before going to bed and the first thing I do when I wake up in the morning. Which I suppose makes me the digital equivalent of a chain smoker.

Hard as it may be to imagine life without Google, Facebook, and Twitter, it's a good idea for those of us old enough to have lived a good portion of our lives without them to remind ourselves and everyone else of what the world used to be like — and to take account of how they have changed the political dimension of it for the worse.

Google's political influence is the least pernicious, but it has nonetheless played a crucial role in the disaggregating of information and concomitant dissolution of the power of every gatekeeper other than itself. Back in the 1990s, if I wanted to read up on the latest bill working its way through Congress, or the progress of NATO's military campaign in the former Yugoslavia, or the likely theme of Bill Clinton's upcoming State of the Union message, I had no easy choice beyond reading newspapers and magazines, watching network or cable news broadcasts, or listening to news radio. In all cases, what I would learn about these subjects, or any other topic of political import, would be determined by what the editors and news directors at these outlets chose to publish or broadcast on any given day. They decided what was important, and that decision shaped my understanding of the world.

But today, if I want to learn something about Joe Biden's infrastructure bill, or Donald Trump's plans to start his own social media company, or whether Democrats really favor defunding the police, I will probably do a Google search about these topics. Those searches will provide me with a long list of articles to read, which will be fabulous. But those articles will be disaggregated from the news outlets in which they appeared and therefore ripped out of any kind of broader context curated by editors. Now the curation process is controlled by Google, which provides me with a ranked ordering of selections to read based on some mysterious mix of what's most popular, what my past search history tells them about what I probably want to read, and whatever additional criteria Google wants to use (including the priorities of advertisers).

It's a seemingly small thing, but nonetheless an important one. Just as albums have become less significant to the music business as consumers have gained the ability to stream and purchase individual songs, so individual articles, columns, and "takes" now exist apart from the news outlets that produce them. That gives Google enormous power to shape public opinion in the subtlest of way — by sorting the information we see. It also allows individual consumers of news to decide, in a much more decisive way than they used to by skipping some articles in the morning paper, what they will read and what they will screen out. And these decisions get magnified and reinforced in every future Google search — and on other social media platforms.

And on none more so than Facebook. It's significant that Facebook calls the items you see when you visit the website your "News Feed." This isn't the News Feed, or Facebook's News Feed. It's your News Feed, curated just for you, based on which items in your News Feed the days and weeks and months before inspired you to click the "Like" button that hovers there below every single post. Every click gives Facebook information about your preferences and prejudices, which it sells to advertisers and uses to make your News Feed ever-more-perfectly (meaning: ever-more-personally) tailored to you.

With every visit to Facebook, your preferences and prejudices get more strongly enforced. You become more of who you were already inclined to be. Conservatives become more intense conservatives. Progressives become more intense progressives. Not always or every time. But enough that the aggregate effect is to contribute in ways we still don't fully understand to ideological and partisan polarization, with each of us networked together with the likeminded and siloed off from everyone else. And that process of political factionalization in virtual space can also help to build factionalism across vast distances in the real world — with dire real-world consequences, as all of us saw on this past Jan. 6 in the nation's capital, when likeminded Trump supporters from around the country who believed his lies about voter fraud traveled to Capitol Hill for an insurrection against the results of the 2020 election.

A similar process takes place on Twitter, but with an added twist that makes it uniquely toxic. On Facebook, you choose your friends, in most cases based on real-world relationships that are mutual and reciprocated online. But on Twitter, you follow people you usually don't know in real life but are aware of because of something they wrote or did or said that you liked or agreed with or hated in a way that resonated with you.

This creates an incentive structure for every person on Twitter that mirrors the outlook of business owners and advertisers. Joining Twitter is like opening up shop on a busy public square teeming with potential customers and trying to tempt them to come in and buy something. What you're selling are the opinions you generate. For your "business" to do well, your takes need to be hot, or edgy, or funny, or antagonizing enough that some of the people who already follow you will retweet some of them, bringing your takes to the attention of a wider circle of potential followers/customers.

If you want to expand on that audience, you need to keep it entertained by giving its members what they wanted when they followed you in the first place. If you want to keep them from abandoning (unfollowing) you, you need to take care not to dash their expectations. As with Facebook, what you've already shown yourself to be gets more deeply reinforced every day, with consistency rewarded and inconsistency or unreliability discouraged. Every person on Twitter is like a stand-up comic on her very own stage, performing for the mob she's cultivated, hoping its members stay happy, keep laughing or screaming, and bring in a bigger and even more appreciative audience tomorrow.

When this incentive structure melds with politics, the result is the most potent means of organizing, rallying, and channeling populist energies the world has ever seen. If you don't believe me, just think of the know-nothing reality-show celebrity who used Twitter to take over a major political party and become president of the United States.

Back when I was first introduced to Google 20 years ago, it would never have occurred to me that such a thing was possible. But now it is, and we've barely begun the process of figuring out what, if anything, we can do about it.