Trump rallies for embattled Senate seats after Halloween bash detour

Hello! Welcome back to the daily briefing on the US midterms campaign trail. We're now just one day out from election day.

You can read more about concerns that the Trump administration may try to interfere with the election results here.

I've been talking about a couple of Senate races that will likely decide who ends up with control of the chamber. Another race we'll be watching closely this week is Texas. North America correspondent Kamin Gock is there at the moment. I messaged him about the state of play.

You're in Texas this week, covering a US Senate race that's been getting plenty of attention. What makes it so interesting?

The last time Texas voted for a Democratic senator was 1988, but the Republican candidate this time, state Attorney-General Ken Paxton, has been plagued by scandals. He was impeached by his own party over bribery allegations but later acquitted, his wife accused him of adultery and filed for divorce on "biblical grounds", and he faced securities fraud charges (he pleaded not guilty) but they were dismissed after he reached a deal to avoid a trial. He has Trump's endorsement but Republicans have not united around him. Meanwhile the Democrat in the race, James Talarico, is a Presbyterian seminarian who's raised a lot of money. Polls suggest it's a really close race. If Talarico can flip the Texas seat, it will be a crushing defeat for the Republican Party.

This is the most expensive US Senate race ever. Financial tracking shows combined advertising spending has topped $US500 million ($711 million). Is there any sign that all this money is making a difference?

The amount of money pumped into this race is crazy and the political ads are inescapable. Elon Musk, a Texas resident with major business interests in the state, gave $US158 million to a group backing Paxton and it's been pumped into campaign. Talarico has tried to seize on this, arguing Musk wants his own senator to control in Congress. Polling appears to be tightening up between the two candidates — but it's also hard to know how many people are left to convince, and how many feel totally over-saturated by ads and aren't listening anymore.

US President Donald Trump might not be up for election at the midterms, but his popularity will have a strong influence on 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 same time tomorrow with more.