With Vice President Kamala Harris serving as the 51st tie-breaking vote, as US Vice President presides over the Senate, the Democrats have managed to retain control of the Senate.?

The US parliament is called US Congress. It has two chambers. The upper chamber is the Senate and the lower chamber is House of Representatives.

In the 435-member House, the Republicans are projected to win the majority, with NBC News showing Republicans have already crossed the 218-majority mark.

Here we explain what the Democratic victory in Senate means, how they defeated Republican 'Red Wave', and what the mid-term polls meant for US President Joe Biden and his primary challenger Donald Trump.

US mid-term elections explained

The mid-term elections are held in the middle of a presidential tenure and that's why they are called so.

They are often considered to be a referendum of sorts on the serving president and the future prospects of the president and their challengers.

In the US mid-term elections, several Senate seats, House seats, state legislatures, and state governors go on the ballot together.?

Formal results can take up to weeks to be announced, so news and polling organisations track the counting and run mathematical projections. Based on this, they make a 'call' who has won a particular electoral contest.?

The main significance of the mid-term election lies in the fact that if the party of the sitting president loses in Congress, the Opposition party can then disturb the president's legislative agenda. For example, if Republicans would have secured majorities in both the House and the Senate, they would have dealt a major blow to Biden, who is pressing for legislations on issues such as gun control, abortions, etc.?

What we know of US mid-term election results

Multiple organisations such as NBC News, FiveThirtyEight, Decision Desk HQ, Fox News, and CNN have projected that Democrats have won control of the US Senate.?

The projections also put Republicans in a comfortable position to secure majority in the House. NBC has projected that Republicans have already secured majority in the US House with 219 seats.?

As of Saturday evening (India time), the Democrats?and Republicans were tied at 49 each in the Senate and the question of the control of the Senate fell on two seats of Nevada and Georgia states. While the result of Georgia would not be known until December 6 when it will hold a 'run off' election, the Republican candidate was leading with a narrow majority at the time in Nevada. The Democratic candidate, however, emerged victorious by Sunday morning.?

A run-off election is a second round of election that is held when no candidate secures 50 per cent of the votes. Notably, the Democratic Party candidate has secured the most votes in Georgia. It has gone to run-offs as a third Independent candidate secured enough votes to deny both the Democrat and the Republican candidates the chance to secure 50 per cent votes.

Takeaways from US mid-term polls

There are three clear take-aways from US mid-term polls, as per the latest results.

One, Democrats have beaten the Republican 'Red Wave'. Republicans were expected to win 54-55 seats in the Senate but they have failed to secure even 51 seats needed for a simple majority.

Two, despite their unexpectedly poor performance, the Republicans are still projected to win the House, which would put them in control of one chamber of the US Congress and give them more bargaining power in government affairs.?

Three, Trump has emerged as the loser of the election and Biden has got a breather, who was dealing with low approval ratings and flak over decades-high inflation and the general state of the economy. Trump's position as the leader of the Republican Party is also under question as the party performed poorly under his stewardship.?

Roe Wave Vs Red Wave: How Democrats Won

The abortion issue, which came to the fore with the US Supreme Court's overturning of earlier Roe Vs Wade verdict, is believed to have played a key role in the Democrats' good performance against the Republicans.

Democrats made abortion rights central to their electoral pitch and it worked as most Americans favoured abortion rights despite SC verdict.

The Associated Press reported, "Nationally, VoteCast showed that 7 in 10 voters said the Supreme Court's decision on Roe v. Wade was an important factor in their midterm decisions. It also showed the reversal was broadly unpopular. And roughly 6 in 10 said they favour a law guaranteeing access to legal abortion nationwide."

Trump's key role in Republican campaign and selection of wrong candidates also played a role in the Republican setback. It has also been said that Trump made the mid-term more about him instead of the candidates who were actually on the ballot. This meant weak candidates went on the ballot and could not win.

The Washington Examiner notes, "Republicans thought the midterm elections would be run on their preferred topic: criticising Biden and Congressional Democrats over a limping economy. Yet the Nov. 8 results show there was more potency than had been widely predicted for Democratic-favored issues, including abortion rights...From his Mar-a-Lago estate in South Florida, the former president [Trump] has tried to play captain and kingmaker for Congressional Republicans...That’s not how the midterm elections turned out for Trump, though. Many of his hand-picked candidates were defeated or struggled in otherwise winnable races."

Not just the Republicans failed to wrest a certain number of Democrats-held Senate seats, they also lost one seat to Democrats held by them. ?

The situation in which one party wins a seat held by the other is called a "flip". Democrats flipped the Pennsylvania Senate seat.?

The Pennsylvania flip was also significant as it had turned into the most high-profile mid-term contest and a proxy contest between Biden and Trump as both of them had endorsed the rival candidates and had campaigned for them. It also turned into the most expensive contest with the overall spending touching $200 million.?

US mid-term result: Biden - 1, Trump - 0

The mid-term results have put Biden in a better position than Trump. In fact, Trump's hold over the Republican party is also uncertain. This is because his pitch against Biden failed and his most-favoured candidates lost and he is roundedly considered a leading cause of Red Wave's failure.

"The midterm election results strengthened President Joe Biden’s hand and weakened former President Donald Trump’s. That is the starting point for the road to the White House," notes Examiner, adding that Biden appears to have performed better in mid-term polls than former Democratic Presidents Barack Obama and Bill Clinton. Both Biden and Clinton went on to serve second terms.

Examiner further notes, "Biden was the big Democratic winner. He was able to hold together the anti-Trump coalition enough to stave off defeat in a number of competitive races. His campaign travel schedule, anti-MAGA [Make America Great Again] messaging, and predictions that the race would swing back toward the Democrats in the end appear to be vindicated. He looks stronger than Clinton or Obama did the day after their first midterm elections, and they both won a second term."

Moreover, the victory of Florida Governor Ron DeSantis puts him in a good position to emerge as a Republican Presisdential candidate against Biden in 2024. Trump has mocked DeSentis.

The most high-profile loss for Republicans and Trump came in Pennsylvania where the contest turned into a proxy battle between Biden and Trump. The Biden-backed Democrat Lt. Gov. John Fetterman defeated Trump-backed Mehmet Oz.?

Pennsylvania is expected to be a key swing state in 2024 US presidential elections and that's why the result is significant.?