Swing states hold key to battle for White House
The stakes for Donald Trump and Hillary Clinton were enormous last night as half of America's likely voters said they would be relying on the presidential debate to help them make their decision in the election on November 8.
Some 50pc said the three debates over the next month would help inform their decision of who to support, according to a Reuters/Ipsos poll released yesterday.
That included 10pc who said they were not currently leaning either way and their votes were up for grabs.
The two candidates were facing off at Hofstra University in Long Island, New York, for their first of the three one-on-one debates.
It was expected to draw a Super Bowl-sized audience of 100 million Americans.
Many voters hoped the debate would take a civilised tone, with 61pc saying they were not interested in personal attacks and name-calling.
Mrs Clinton currently leads in most national polls. The latest Reuters/Ipsos poll found Mrs Clinton leading Mr Trump nationally by four points.
On election night on November 8 the same viewing public will be bombarded with breathless pronouncements as the results come in from each of the fifty states.
State by state the map will be filled in, blue for Hillary Clinton, the Democrat, and red for Donald Trump, the Republican, with the candidates claiming the electoral college votes of each state they win.
The reality is, though, that we can already fill in the vast majority of America's electoral map in deep blue for states like California and bright red for states like Alabama.
It is only in smaller set of "swing states" - sometimes called "purple" states - that the outcome is truly in the balance, and it will be in those states that the election is won and lost.
What is a swing state?
Swing states are so named because they swing back and forth between parties depending on the election.
Simply put, they are states which are relatively evenly divided between Democrats and Republicans. Depending on who you ask there are anywhere from eight to fifteen competitive states this time around.
The key states for the 2016 election can be split into three categories.
The crown jewels
In recent cycles, the presidency has been won in Florida and Ohio. America's 3rd and 7th largest states with 29 and 18 electoral votes respectively, they are constantly swinging back and forth between parties.
The two states also have near-perfect records of picking the president over the past five decades. The result in Ohio has mirrored the national outcome in every election since 1960, while Florida has diverged from the nation at large just once over that period.
It is unsurprising, therefore, that both Mr Trump and Mrs Clinton are focusing a great deal of time and resources on Ohio and Florida.
Because of demographic shifts in the US, paired with Mr Trump's unpopularity, states that were once solidly Republican are now within reach for the Democrats in 2016.
When Barack Obama won North Carolina in 2008, he was the first Democrat to do so since Jimmy Carter. Mitt Romney won the Southern state back in 2012, and it now appears to be a toss-up between Mrs Clinton and Mr Trump.
The Democratic nominee hopes to expand the map with wins in Arizona, Georgia and Missouri, all of which have consistently voted Republican for nearly two decades.
Because of the realities elsewhere on the map, Mr Trump cannot afford to let those states change hands in 2016.
'Obama coalition' holdovers
Mr Obama won the electoral college by wide margins both in 2008 and 2012, and he did so by taking traditional swing states like Iowa and Pennsylvania.
Lastly he utilised his popularity among suburban voters to turn states like Virginia (and North Carolina) blue.
Mrs Clinton looks likely to hold on to Colorado, Pennyslvania and Virginia, with Iowa and Nevada still hanging in the balance.
She is also facing a stronger-than-expected challenge in New Hampshire, which has voted for the Democrat in every recent election except 2000.
Why does Donald Trump need to win more swing states than Hillary Clinton?
If you remove the twelve states named above from the equation, and allot the other 38 states to their probable winners, Hillary Clinton holds an electoral college lead of 226 to 154, with 270 needed to win.
Add in her likely victories in Colorado, Pennsylvania, New Hampshire and Virginia and Mrs Clinton is across the threshold with 272 electoral votes.
Mr Trump therefore needs to hold on to every state he is expected to win, sweep all eight of the other swing states including Florida, Ohio and North Carolina, and pluck at least one of those four states from Mrs Clinton's grasp.
For Mr Trump to win, nearly all of the swing states will need to swing his way. (©Daily Telegraph London)