Former Florida governor Jeb Bush is entering a presidential contest vastly different in size, pace and cost to those which his father and brother took part in. Photograph: Joe Raedle/Getty Images

Nearly 27 years after his father was elected president, moulding a political dynasty that would propel one son into a governor’s office and another in(...)

Hillary Clinton at Texas Southern University, Houston, where she delivered her most aggressive speech since she announced she was running for president.  Photograph: Pat Sullivan/AP Photo

Republican senator Ted Cruz was firing up conservatives gathered to support his colleague Pat Roberts, who was struggling to hold on to his US Senate (...)

Temperature buoy, Nantucket Sound. Once recordings are adjusted  to compensate for  problems in the way   temperatures were measured, a perceived global warming slowdown largely disappears. Photograph: National Oceanic and Atmospheric Administration via The New York Times

Global warming has not undergone a “pause” or “hiatus”, according to US government research that undermines one of the key arguments used by scepti(...)

The US government’s bulk collection program was first revealed by documents obtained by the former NSA contractor Edward Snowden

The US Senate on Tuesday passed a bill that would end the bulk collection of millions of Americans’ phone records, the most significant surveillance r(...)

Lindsey Graham, a three-term senator from South Carolina, cited the increasing violence in the Middle East as motivation for his decision to run. Photograph: Win McNamee/Getty Images

Senator Lindsey Graham, a foreign policy hawk, has become the latest Republican to join the party’s fast-growing field of presidential candidates. Mr (...)

Former Arkansas governor Mike Huckabee, holding his grandson Chandler, as he formally launches his bid for the 2016 Republican presidential nomination during an event in Hope, Arkansas, on Tuesday. With Mr Huckabee is his wife Janet, holding granddaughter Scarlett. Photograph:  Mike Stone/Reuters

Republican Mike Huckabee entered the race for his party’s 2016 presidential nomination on Tuesday, looking to break out from an ever-widening field by(...)

Former Hewlett-Packard CEO Carly Fiorina: “I think I’m the best person for the job because I understand how the economy actually works. I understand the world, who’s in it, how the world works.” Photograph: Jim Young/Reuters

The 2016 US presidential field has grown, with Carly Fiorina, the former chief executive of computer maker Hewlett Packard, and retired neurosurgeo(...)

US senator Marco Rubio has announced that he is to seek the Republican nomination in the 2016 presidential election.  Photograph: Jim Lo Scalzo/EPA

US senator Marco Rubio of Florida told top donors that he will run for the White House because he is “uniquely qualified” to represent the Republican (...)

Hillary Clinton announced her campaign for the US presidency in a video posted to hillaryclinton.com.   Photograph: Hillary For America via AP

Hillary Rodham Clinton has officially launched her second attempt to become the first female US president, firing the starting gun on the 2016 pres(...)

Hillary Clinton: I’m getting ready to do something too . . . I’m running for president. Photograph: Pete Marovich/Bloomberg 0:52

Hillary Rodham Clinton on Sunday officially launched another attempt to become the first female president, ending years of speculation and firing the (...)