Democrats chewing nails as Trump targets controversial Senate pick

If your social media algorithms have been even slightly infiltrated by US politics, you may have heard chatter about "the primaries".

It's a big year for stateside voters, and these races are just the beginning.

Primary elections are the first step in electing who represents voters across the country in the House of Representatives and the Senate.

So here's what to know about the primary elections, from the basics to the downright quirky.

Aren't Americans going to the polls later this year?

Yes, they are.

The midterm elections, which decide the make-up of the House of Representatives and a third of the Senate, are slated for November 3.

That election will be a big deal, as it will decide how much power US President Donald Trump has to get laws passed.

All the politicians who will be running for seats during the midterms are fighting for their places on the ballots right now.

In a nutshell, that's what the primary elections are!

Political parties use them to select candidates for a general election in most states.

So, how do primary elections work?

The majority of primaries go ahead between May and August.

Who can vote in them depends on the type of primary, which differs between states.

Tell me about some of the races

With more than 400 congressional seats up for grabs this year, you can imagine the sheer number of primary races playing out right now.

For the most part, how they play out is fairly unremarkable, especially for us here in Australia.

But some races have taken unusual turns.

The one everyone's talking about

Analysts say Democrats have a chance of taking Maine. ( ABC News )

Democrats are the favourites to have control of the House of Representatives when the midterms are said and done.

But flipping the Senate will be more of an uphill climb.

The party would need to win at least four seats, and most of those up for grabs are in Republican-leaning areas.

That brings us to the north-easternmost state of Maine.

Analysts say it's a seat Democrats have a better shot at turning blue, even though the current senator, Republican Susan Collins, has represented it since 1997.

Democrats are pinning their hopes on newcomer Graham Platner, a military veteran and oyster farmer who easily won the primary election on June 9.

But elements of his personal history have left some in the party chewing their nails.

It was revealed last year that he had a tattoo of a skull-and-crossbones symbol adopted by a Nazi parliamentary unit.

His wife internally flagged sexually explicit texts he sent to multiple women last year as a campaign liability, and former girlfriends have told the New York Times he at times displayed volatile, troubling behaviour toward them.

Mr Platner has apologised for the behaviour, and said he struggled with post-traumatic stress disorder and depression following combat duty in Iraq and Afghanistan.

He said he did not know the tattoo resembled a Nazi insignia and had it covered up last year.

Graham Platner won the Maine primary easily. ( Reuters: Amanda Sabga )

Progressive backers, including Senator Bernie Sanders, have stuck with him and no prominent figures in the party have called for him to drop out.

Still, some party members worry Mr Platner's past could lose them the vital seat.

US President Donald Trump has attempted to leverage the perceived weakness, lacing into Mr Platner on Wednesday.

"He's a thug, and they're trying to make excuses for him," Mr Trump said of top Democrats. "I mean, he's worse than any human being that's ever run for office, probably."

The president has previously faced allegations of misconduct with women , was once caught on audio bragging about grabbing women "by the pussy" , and was found liable by a New York jury for sexual abuse.

The tale of two Dans

Alaska, the most north-western state, may have two Republicans named Dan Sullivan on the ballot. ( ABC News )

In the north-westernmost state of Alaska, Republican Dan Sullivan hopes to retain his Senate seat at the midterms.

To do so, he'll have to beat Republican candidate Dan Sullivan.

That's not a typo. There really are two Republican Dan Sullivans in this race.

All that will separate them on the ballot is their middle initials: an S for the incumbent and a J for the challenger.

Their campaign branding is almost identical, too, with both employing similar colours, fonts and star iconography.

The campaign logos of Dan S Sullivan (top) and Dan J Sullivan (bottom) are almost identical. ( Supplied: Sullivan for Alaska/Sullivan for Senate )

If that's not confusing enough for voters, the drama could continue all the way to November.

The state's primary is slated for August 18, but its rules allow the top four vote-getters to advance to the midterm, even if they're registered with the same party.

Republicans fear Dan J Sullivan could end up in the final four and confuse voters enough that neither gets the majority, handing Democratic candidate Mary Peltola an easy win.

Dan S Sullivan accused Democrats of recruiting…