With the US presidential campaign in its last hours, it's time to make The Call: Hillary Clinton will be elected president with at least 274 electoral votes.

The magic number for election as president is 270.

To parse this year's electoral map, let's start with 2012, when Barack Obama defeated Mitt Romney, 332 electoral votes to Romney's 206:

US presidential election 2012 results. ( Supplied: 270towin.com )

The 2012 result shows that to win this year, Trump needs to carry all the states won by Romney, plus Ohio (18), Pennsylvania (20) and Florida (29) – to reach 273 and victory.

The projection made here today is for Clinton to carry the 2012 Obama states minus states where she is trailing or threatened:

Florida – 29

Florida – 29 Ohio – 18

Ohio – 18 New Hampshire – 4

New Hampshire – 4 A Maine Congressional District 1 – 1

A Maine Congressional District – 1 Iowa – 6

This results in an electoral college total of 274:

Electoral College map shows Hillary Clinton winning 274 votes ( Supplied: 270towin.com )

What this projection means is that if Clinton also carries North Carolina – which Romney won in 2012 – that would be a huge boost, adding another 15 electoral votes to her total, taking her to 289, and giving her a buffer should she lose say Colorado (9) and /or Nevada (6).

Electoral College map shows Hillary Clinton winning 289 votes. ( Supplied: 270towin.com )

A Clinton win in Florida, with or without North Carolina, would place her over 300.

What would upset this projection?

The projection made here today is that, without Pennsylvania, Trump cannot win, even if he carries Ohio and Florida – unless he is able to also capture Michigan and Wisconsin. Both states have voted Democratic in the last six presidential elections.

A Trump win in Pennsylvania (20) would be very difficult for Clinton to make up. The loss of Pennsylvania together with Florida would be a real blow to her chances.

What to watch for as the returns come in?

If New Hampshire goes for Trump, it will signal a major Trump effort with those irascible flinty New England voters has come good – and will give him an early election night boost.

If goes for Trump, it will signal a major Trump effort with those irascible flinty New England voters has come good – and will give him an early election night boost. If Clinton loses Virginia – a major upset in her vice president's home state, and a signal of a very bad night for her.

If Clinton loses – a major upset in her vice president's home state, and a signal of a very bad night for her. Pennsylvania is a must hold for Clinton. It is no coincidence that her final rally, with President Obama, is in Philadelphia on Monday night. A loss there, unless made up in Florida, means a likely loss of the election.

is a must hold for Clinton. It is no coincidence that her final rally, with President Obama, is in Philadelphia on Monday night. A loss there, unless made up in Florida, means a likely loss of the election. Florida will show the power and depth of the Hispanic anti-Trump vote and the Clinton turnout machine.

will show the power and depth of the Hispanic anti-Trump vote and the Clinton turnout machine. North Carolina will show whether the Obama-Clinton full court press and ground game has paid off – and would be a big takeaway from the 2012 Republican win.

will show whether the Obama-Clinton full court press and ground game has paid off – and would be a big takeaway from the 2012 Republican win. A Trump upset in Michigan and Wisconsin would overturn Democratic control of the Midwest industrial heartland and signal a reordering of the American political landscape by Trump.

A Trump upset in would overturn Democratic control of the Midwest industrial heartland and signal a reordering of the American political landscape by Trump. Colorado and Arizona will be further harbingers of whether the West is really becoming Democratic territory for the future.

This projection is based on an assessment of the state of play across the country; a judgment that the Clinton ground game will deliver the turnout required to win, particularly with women, Hispanic Americans, African Americans, Muslim Americans, and younger voters; that Trump has made decisive errors in driving apart Americans by gender, race, religion, and ethnicity; that the United States 2016 election is not Brexit II; and that the American people in their wisdom will not allow themselves to be led into the abyss by a person so dangerous and destructive of American democracy and values – something he has proved every day he has been a candidate for President of the United States.

It is Hillary Clinton who will claim victory, and take the country forward.

Bruce Wolpe was on the Democratic staff in Congress in President Obama's first term. He is a supporter of Hillary Clinton's campaign. He is chief of staff to former Prime Minister Julia Gillard. The views posted here are solely and exclusively his own.

1 Maine and Nebraska allow their electoral votes to be split by Congressional districts (electorates). One Maine congressional district is leaning to Trump. Trump is also favoured in all of Nebraska's congressional districts.