Democratic victories in the Georgia runoffs ended Mitch McConnell's 6-year tenure as Senate Majority Leader and DC's most feared power broker

• The Democrats' victory in the Georgia runoffs was a disaster for Senate Majority Leader Mitch McConnell, costing him his dominant role in the Senate.
• McConnell has been majority leader for six years, but once the Biden administration begins, he'll be the minority leader.
• He'll also lead a Republican minority fractured by internal conflict and with no allies in the White House.
• The changed circumstances will greatly diminish McConnell's powers, though he and the 49 other Republican Senators may still disrupt Democrats' agenda.

Victory for both Democrats in the Georgia runoffs will bring to an end Mitch McConnell's six-year tenure as Senate Majority Leader, in which he was often characterized as one of the most powerful men in Washington, DC.

According to projections by Decision Desk HQ and Insider, both Jon Ossoff and Raphael Warnock beat Republican incumbents in the Georgia votes, unseating Sens. Kelly Loeffler and David Perdue.

This deprives Republicans of their majority, leaving 50 GOP Senators across the aisle from 48 Democrats and the two independent Senators who reliably vote alongside them.

Read more: Here's what the Georgia Senate results mean for voting rights, cannabis, and $2,000 stimulus checks

Once Vice President-elect Kamala Harris, a Democrat, takes office, she'll be a tiebreaking vote, giving Democrats control of the Senate for the first time since 2015.

It'll be the party's first time in control of the Senate, House of Representatives, and White House all at once since 2011.

McConnell is a casualty of this electoral realignment. The Kentucky senator served as the majority leader since 2015, which gave him enormous power over proceedings.

His six-year tenure is the longest a Republican has held the role, but is now in its final days.

He is due to swap places with the Senate Minority Leader Chuck Schumer, a Democrat, and become the minority leader himself - meaning he longer decides what happens on the Senate floor.

This is the position he held before 2015, when Democrats last controlled the Senate.

Schumer previously said that Democratic control of the Senate "would be the biggest difference maker" for Biden enacting his plans.

McConnell would still be powerful in the minority, leading a group of 50 Republicans who could stymie any measures which don't have total support from Democrats.

But his ability to block Democratic ambitions would be far less pronounced, giving President-elect Joe Biden and his allies a path to enact legislation to further their agenda.

McConnell may also struggle to exert as much control over his party, reeling from losing the White House and Senate at once, and split over how to handle the attempts by outgoing President Donald Trump to overturn the election results.

As The Atlantic reported, McConnell in a recent private call, urged Republicans not to object when Congress votes to certify Biden's win on Wednesday. But several Republicans senators plan on doing so anyway.

Some in the party may also blame McConnell for the outcome in Georgia.

As Business Insider's Mia Jankowicz reported, McConnell stood in the way of Congress passing $2,000 stimulus checks, which became a pivotal issue in the election.

For now, Democrats are celebrating the prospect of a diminished McConnell.

This is from California Gov. Gavin Newsom:

And this is from Rep. Ted Lieu of California:

Andrew Yang, a former Democratic presidential candidate, also weighed in:

As did Massachusetts Rep. Joe Kennedy:

And California Rep. Katie Porter:

Though he will likely remain a force to be reckoned with, Minority Leader McConnell will not be capable of the all-out obstruction that many Democrats until recently had been fearing.