Cruz received $675,000 in direct contributions from oil and gas company employees, while Bush trailed behind at $420,600, according to the Center for Responsive Politics. Democratic candidate Hillary Clinton came in third, with $226,000, edging ahead of Republican Marco Rubio.
Republican front-runner Donald Trump only received $8,164, even less than Democrat Bernie Sanders, who has been a vocal advocate of strong climate change policies throughout his campaign.
In December, Trump blasted Cruz at a rally in Iowa, claiming that oil companies contributed heavily to his campaign.
"With the ethanol, really...[Cruz] is gonna come a long way now, for the oil," Trump said. "But I understand it. Oil pays him a lot of money. He's gotta be for the oil, right?"
Many of the candidates listed in the below graph have since suspended their presidential bid — notably Republican Carly Fiorina, Mike Huckabee and Democrat Martin O'Malley. But the Republican Party has received over 80 per cent of the oil and gas contributions, eclipsing Democratic candidates. Cruz did not raise as much funds as Clinton and Bush, however, in other industry areas such as pharmaceuticals, education and hedge funds.