All political eyes are trained on the state of Alabama today for a special Senate election.

The Irish-American former chief strategist to President Donald Trump, Steve Bannon, well summed up today’s election, describing it as "a national election".

Speaking at a rally for the Republican candidate Judge Roy Moore, Bannon said "it is the Trump miracle versus the nullification project".

(He regularly accuses "the left" of trying to "nullify" the 2016 election result, equating it to the Nullification Crisis that President Andrew Jackson faced in 1832. Both Bannon and Trump are fans of Jackson, viewing him as the original populist president.)

Ultimately in the case of the importance of this election, Bannon is right. It is "a national election" of sorts.

The whole country - or at least the part still engaged by what is going on in the White House and in Washington - is tuned to Alabama.

Polling shows the Democratic candidate, Doug Jones, is in with a chance of winning, in a state where Donald Trump got almost twice as many votes as his Democratic rival Hillary Clinton last year. 

Republicans will be hoping that "Trump miracle" dust will be spread liberally across the state as voters go to the polls.

But why does it matter so much?

At any other time, a special election in the majority Republican state of Alabama in mid-December for a Senate seat vacated by a party member who went on to become the Attorney General and sit in the president’s cabinet would be a done deal.

But we're not in "any other time".

We're in a time of great change, when all political rule books were ripped up, burned or thrown out in late 2015 and throughout 2016. 

This time it's different for a few reasons. Firstly, despite holding all three links in the lawmaking chain of power (the House of Representatives, the Senate and the White House), the Republican party has struggled to pass any laws through Congress.

They hold only a narrow majority in the Senate, just 52 seats, and on several occasions it's their own party members who have caused legislation to fail (don't mention the Repealing Obamacare war).

Currently the GOP can only afford to lose four of their own at any time, relying then on the deciding vote of the vice president.

If they lose the seat held by Jeff Sessions tonight, they will only be able to lose two of their own, before the vice president would have to cast the deciding vote.

With John McCain and others almost running an opposition party within the party, that is an incredibly shaky majority.

On the other hand, a win for the Democrats tonight would represent an astonishing victory.

Not only does it help shore up the majority, but it would bolster confidence in a party that still does not look to be on any sort of strong footing heading into next year's mid-term elections, let alone the 2020 presidential contest.

It would also underline for party operatives that the victories in the Virginia down-ballot races last month were not an aberration.

And to do so in such a Republican stronghold, one where a Democrat has not won a state or gubernatorial contest for 20 years would be remarkable.

But Democrats would be wrong to read too much into a prospective victory, or into the close race.

It is not necessarily a case that they are doing so well, but rather that the Republican Roy Moore is doing so badly.

He's been dogged by multiple allegations that he pursued teenage girls while he was in his 30s, and working in the district attorney's office. In one case it is alleged that one of the girls was only 14 years old.

Judge Moore rejects these allegations entirely, and questioned at a rally last night why these accusers were making such public statements now, about events that happened decades ago. 

Senior party members in Alabama, including sitting Senator Richard Selby and former Republican Secretary of State Condoleezza Rice have urged fellow Republicans not to back Moore.

If he does win, that would also be a remarkable victory under the circumstances.

Moore is a former Alabama Supreme Court judge. Doug Jones is a former US attorney.

In a state which attracted national attention during the civil rights movement, Jones helped prosecute and convict two members of the Ku Klux Klan responsible for the 1963 bombing of the 16th Street Baptist Church in Birmingham, which killed four young girls. 

President Trump had initially endorsed the other Republican candidate in the primary contest Luther Strange, only backing Moore last Friday.

The sexual misconduct allegations relating to Moore, and to others in all walks of public life recently, have coincided with a resurgence of the allegations made by 16 women against the president ahead of the 2016 election.

The women have made a documentary and are currently on a press tour promoting it.

Some 50 Democratic lawmakers have written to the chair and ranking member of the House Committee on Oversight and Government Reform asking them to open a congressional investigation into the allegations against the president.

The US Ambassador to the UN Nikki Haley said on Sunday that the women "deserved to be heard". 

Asked about it at the White House press briefing yesterday, Press Secretary Sarah Huckabee Sanders said the president rejected the allegations, but in any event, she said the voters knew about them going into last year's election, and voted for him anyway.

The Republican party, and Judge Roy Moore, will be hoping a similar logic applies to the voters of Alabama today; that there will be a desire for what Steve Bannon calls the "Trump Miracle".

Polls close at 1am Irish time tomorrow morning. Follow @caitrionaperry for updates through the night.