The US mid-term elections in five days' time will help define the rest of Donald Trump's presidency.

Americans will vote for members of both chambers of Congress, as well as for governors in 36 out of 50 states.

Between now and then, we'll bring you updates and all the best analysis every weekday in this round-up.

Today's edition includes a controversial ad and the #Blexit movement explained.

One controversial ad

With less than a week before the vote, President Trump has posted a divisive campaign ad on his Twitter account.

The video, now pinned to the top of his social media feed, blames the Democrats for "letting in" Luis Bracamontes - an undocumented immigrant from Mexico who killed two police officers in Sacramento in 2014.

Bracamontes, who had previously been deported twice, was sentenced to death for the murders earlier this year.

The video posted by President Trump shows Bracamontes grinning in court and threatening to "kill more cops soon".

"Illegal immigrant, Luis Bracamontes, killed our people! Democrats let him into our country. Democrats let him stay," the video captions read.

Democratic National Committee Chairman Tom Perez told CNN that the ad showed "distracting, divisive Donald at his worst" and accused the president of "fearmongering" with the ad.

In comments beneath the video, Twitter users pointed out that white American citizens had been responsible for a number of mass shootings, including the recent attack on a synagogue on Saturday that left 11 Jewish worshippers dead.

Many also drew comparisons to the infamous 1988 "Willie Horton" attack ad supporting former President George HW Bush in his race against Democratic presidential nominee Michael Dukakis.

The ad played to racial fears by highlighting the story of African-American criminal Willie Horton, who raped a white woman after being released from prison as a part of a programme that had been supported by Mr Dukakis.

Lee Atwater, the former Bush campaign manager, apologised repeatedly - even on his deathbed - for that ad.

President Trump has doubled-down on his notoriously strong rhetoric on immigration in recent weeks as the mid-terms near.

On Wednesday, he told reporters that as many as 15,000 troops could be deployed to the border with Mexico as a caravan of Central American migrants makes its way toward the US.

He has also clashed with his House Speaker Paul Ryan over a plan to revoke automatic citizenship rights for children born in the US using an executive order.

After Mr Ryan criticised the plan, President Trump vented on Twitter that he should be "focusing on holding the [Republican] Majority" instead.

One voter surge

Voting monitors are saying that early voting turnout already looks up across the board for the mid-terms - with particular surges noted among young people and non-white voters.

Data company TargetSmart says that over 1.5 million under-30s have already cast their ballot early - compared with only 563,000 in the same time period four years ago.

Battleground states currently held by Republicans, including Georgia and Texas, have shown particularly high early increases in young and African-American voters.

The data echoes polling that suggests next week's vote could see historic turnouts among the under-30s. In 2014, only 19.9% of them voted - the lowest amount recorded by monitoring groups for 40 years.

Both parties have touted the significance of the upcoming vote and National Voter Registration Day in September saw a record 800,000 registrations.

Young activist groups, including the students from Parkland who organised March for Our Lives, have been particularly vocal about rallying and registering first-time voters.

They went on a Summer bus tour through the US to encourage young people to register and recently had celebrities, including Marvel film stars, talk about their "first time" voting in a campaign video.

One piece to read

Many states, the majority of them governed by Republicans, have put in place new legislation in recent years saying they are needed to prevent rampant voter fraud.

Opponents believe this is strategic, and disproportionately targets specific groups, including minorities, to prevent them from voting.

We've taken a look at all the different claims of voter suppression across the country.

One video to watch

The BBC's Rajini Vaidyanathan and Anthony Zurcher explain the "Blexit", or "Black Exit", movement that is encouraging black Americans to vote Republican.

The campaign made headlines earlier this week when rapper Kanye West was linked to it - before he promptly announced his departure from politics.