If you follow US tech, you're probably getting a sense of deja vu.

Senators are about to grill Twitter's Jack Dorsey and Facebook's Mark Zuckerberg.

It's only three weeks since both chief executives testified. But since then the political landscape has wildly altered.

It is Democrat voices now, not Republicans, that arguably pose the greatest threat and will be listened to more closely.

In particular that of Vice President-elect Kamala Harris, who is a member of the Senate Judiciary Committee - though it's not confirmed whether she'll participate

Labelling Trump

After the election, there were fears that social media might fan the flames of chaos, and lead to riots on the streets.

Although there were scuffles in Washington on Saturday night, mass unrest has not materialised. Collective sighs of relief have been heard around Silicon Valley. The world - so far - hasn't imploded.

But fake news and misinformation around the vote have been rife on both platforms.

Twitter and Facebook have labelled misleading content with varying degrees of success.

That has put them once again on a collision course with President Trump.

Howls of discontent from Republican voices greeted Twitter's repeated labelling of his tweets.

Many Republicans are now pushing for people to dump Twitter in exchange for Parler - a "free speech" version of the app.

But there's only so much you can do if Twitter decides to suppress, take down and/or label a tweet.

You can complain to Twitter or leave the platform, but ultimately Twitter decides what action to take. Twitter owns the platform. If you don't like the rules, too bad.

The same goes for Facebook.

That's why Republican senators see this as an opportunity to grill Zuckerberg and Dorsey - their first chance since the election - and to blow off some steam.

But the two CEOs will be aware it's Joe Biden they must now please.

Facebook, in particular, has already been the focus of anger from the President-elect's aides.

Last week, one of Mr Biden's senior advisers attacked Facebook over its handling of conspiracy theories and calls to violence in the days following the US election.

"Our democracy is on the line. We need answers," tweeted Bill Russo, who is deputy press secretary to the US president-elect.

Joe Biden has said previously that he would repeal Section 230 - the law that protects social media companies from being sued for the things people post.

Tech monopolies

In October, Democratic legislators penned a highly critical report into Big Tech. They called companies like Google, Amazon and Facebook "monopolies", and suggested they could be broken up.

So, this will be the first chance to gauge how the Democrats feel post-victory.

Vice President-elect Kamala Harris has a long history with Big Tech.

As state Attorney General in California, she was seen in Silicon Valley as a straight shooter.

It will be interesting to see whether she decides to take this opportunity to put Zuckerberg under pressure.

Other Democratic senators may also see this as a chance to wave their credentials, and audition for cabinet.

For example, Senator Amy Klobuchar has been tipped by some as Biden's pick for attorney general. She's already suggested that Google should be split up.

And Senator Chris Coons - also in the running for a top job - is one of several senators to put their name to a letter on Monday criticising the social network for its response to anti-Muslim content on the platform.

Get ready to hear a lot about how these two companies aren't doing enough to take down hate speech or fake news - with a special focus on Facebook.

It's likely too that Republican Senators Mike Lee and Ted Cruz will ask fiery questions.

But with two months left of a Republican administration, their words carry less of a threat than they did last month.

As power has shifted, so will Zuckerberg's and Dorsey's attention - this is their chance to convince the new rulers that light-touch regulation is best.