Even though Republicans take about as much money as Democrats from private companies, they're more reliably lampooned as being "in the pocket" of big business - and big business doesn't get much bigger than Silicon Valley.
What worry is it of ours how Facebook regulates speech in its domain? What happened to "corporations are people, my friend"?
The key to understanding Mr Zuckerberg's rough ride is twofold: money and history, those two great determinants of why and how things are done in Washington.
After the Supreme Court's Citizens United decision, which granted untrammelled rights of speech to corporations, the line between business and politics has been almost erased.
Companies and unions can give unlimited sums to political action campaigns, which are in turn allowed to support political candidates.
While American business has always lobbied for specific policy outcomes and regulatory objectives, it used to limit itself to areas of self-interest.
Now, indeed like people, corporations are getting into a wider range of issues.
This shift was accelerated by social media itself. Through platforms like Facebook, individuals can now publicly shun companies that don't "reflect their values".
Activist campaigns form and spread with unprecedented speed. Companies, in turn, got savvy and hired social media teams who would mock those who posted comments outside the new bounds of acceptable discourse.
On the playground, we would call that bullying - but in this age of clickbait virtue-signalling, it's good PR.
The result has been the unnecessary politicisation of business. On the Right and Left, private companies engage in social debates (like gay marriage) which have nothing to do with their day-to-day, profitmaking activities.
Nowhere has this been more true than in Silicon Valley, whose companies seek to promote lifestyles, not products.
What constitutes an "acceptable" way of living one's life, of interacting with others and even of thinking, has been narrowed, in recent years, by companies like Facebook.
But this episode was about more than Republicans being unhappy that tech companies have helped to shift most of corporate America leftward (to the detriment of GOP coffers).
Politics aside, the party has a long history of mistrusting any concentration of power.
America was founded as an escape mechanism for those oppressed by capricious monarchs with unrivalled political and economic sway.
Modern Republican ideology stems from the institutional memory of what can go wrong when we have no mechanism to hold powerful people to account.
For all we respect and value private enterprise, Mr Zuckerberg's power to define free speech - which matches any federal judge, and maybe even the Supreme Court - makes us duly nervous.
Breaking up monopolies is in Republicans' blood. Teddy Roosevelt, one of the greatest presidents and a hero of the party, trust-busted his way into the 20th century and set the tone for how the US would handle competition policy.
The impulse to monopolise is an essential component of capitalism - why go into business unless you believe that you can and will be the best at what you do?
But the actual achievement of a horizontal monopoly is rightfully considered unacceptable by a party primarily concerned with individual liberty.
We did not need the 2016 election to know that Facebook has an outsized influence on our national conversation, just as we did not need the revelation that its profits often come from selling the data of its users to know that its intentions are not utopian.
If the Democrats are too cowed to do so, then let us celebrate Republicans for standing up in defence of those people in whom Facebook can see only dollar signs.
