- Video report by ITV News Correspondent Emma Murphy in Washington
During the last presidential election, Donald Trump fought hard to win the votes of the coal workers.
This time around, with the race already underway for the 2020 US Elections, he is facing the prospect of fighting for the green vote.
In the few years that have passed, a new generation is making it clear that those running for the presidency need to take into account the votes of the green movement.
The rise in power of environmentalists has become a global phenomenon.
The headlines generated by Swedish teenage climate activist Greta Thunberg last month as she addressed an Extinction Rebellion rally in London and spoke to British politicians, shows how important the issue is to the younger generation.
ITV News Correspondent Emma Murphy reveals why presidential candidates are being taken to task by Democrat Alexandria Ocasio-Cortez, 29, who is flying the green flag for this demographic.
The youngest woman ever to serve in the United States Congress, Ms Ocasio-Cortez unveiled a Green New Deal, as envisioned by the Democrats, in February this year with the aim of fighting climate change and moving the US to renewable energy.
She told ITV News: ''We need to have a solution on the scale to the problem. And for everyone who says that these solutions and proposals are too radical - they do not understand the radical problem that we are in when it comes to emissions and the destruction that's at hand with climate.''
Her passion, after just four months in office, is proving to be a galvanising force on the younger generation.
Many teenagers and those in their 20s queued up outside Cramton Auditorium in Washington to hear a climate change talk and are buying into her vision.
One told ITV News: ''We have one chance to survive and be healthy as a society and this is it.
''A lot of people around the world should really care about this because it's a real issue and it's really happening. We can't ignore it anymore.''
Democratic presidential candidate Bernie Sanders, 77, echoes Ms Ocasio-Cortez's message.
He said: ''Together we have got to do everything that we can to transform our energy system away from fossil fuels, to energy efficiency and sustainable energy.''
Under the Green New Deal the aim is to switch entirely to renewable zero emissions fuel by 2030.
A recent forecast by a US government energy agency expects the country will still rely on oil, natural gas and coal for its main energy supplies through 2030.
However, ethanol and other renewable energy sources will double during this period.
Visiting a gas company, Cameron LNG export facility in Hackberry, Louisiana, today, Trump made it clear he did not think green issues matter to wider America.
Attacking the views of Mr Sanders, the President said the Green New Deal amounted to job losses and described it as a hoax.
He said: ''Bernie's got a lot of energy, but it's energy to get rid of your jobs.
''The Green New Deal - everybody go home, you've just lost your jobs...The Green New Deal is a hoax like the hoax I just went through.''