Trump spruiks economy as farmer-funded ads attack cost-of-living record

Hello! Welcome back to our US midterms briefing. It's another day on the trail in the US, so let's dive in!

I messaged with North America correspondent Lauren Day about some of the key US Senate races we're watching. Here's what she had to say.

We're going to hear about plenty of races in the coming days. Which do you have your eyes on?

There are too many to mention but I've just been in Michigan where progressive firebrand Abdul El-Sayed is in a tight race with Republican Mike Rogers for a US Senate seat. It will be a test of whether a left-wing candidate can win in a purple state. I'm also fascinated to see whether Democrat James Talarico can turn Texas blue — a holy grail for the Dems.

But the race I’ve really been obsessed with is Alaska. The Democratic candidate there, Mary Peltola, has run on a campaign of Fish, Family and Freedom and is a really fascinating character. But the weirdest thing about that race is the fact there are two men named Dan Sullivan on the ballot, including the Republican incumbent. Trump has been crying foul about "Decoy Dan" and has directed the Justice Department to file a lawsuit seeking to prevent the certification of the results if their Dan Sullivan loses. You can't make this stuff up.

What does it mean for Trump if Republicans lose this election?

If the Republicans lose either chamber, Trump's ability to advance his agenda through Congress could be severely limited and Democrats will have new power to investigate his administration. They could also vote to impeach the president but would need two-thirds of the Senate to remove him from office, which is very unlikely, even if Democrats win the Senate. But of course, executive orders, agency actions and foreign policy don't need congressional approval so those powers would continue, and Trump would still veto any laws Democrats tried to push through Congress.

Want to read more on Lauren's time in Michigan? She wrote a brilliant deep dive on El-Sayed, which you can find here.

US President Donald Trump might not be up for election at the midterms, but his popularity will have a strong influence over the outcome.

The president's party almost always loses House seats in midterm elections and that trend gets steeper when the president is unpopular.

Historic polling data collated by analytics firm Gallup shows presidents with approval ratings below 50 per cent have seen their party lose an average of 37 House seats.

Presidents with approval ratings above 50 per cent have netted smaller loses, with an average of 14 seats.

You can keep track of the latest out of the US here.

Thanks for joining me! I'll be back at the same time on Monday with more.