Donald Trump speaks during the American Israeli Public Affairs Committee (AIPAC) policy conference in Washington,DC on March 21st, 2016. Photograph: Andrew Harrer/Bloomberg

Republican presidential front-runner Donald Trump has confronted doubts about the depth of his knowledge of world affairs, delivering a sober speech t(...)

Democratic presidential candidate former secretary of state Hillary Clinton greets supporters during a ‘Get Out The Vote’ event at Lake Taylor Senior High School on Sunday in Norfolk, Virginia, ahead of Super Tuesday. Photograph: Getty

Voting has begun in the so-called Super Tuesday primaries in which candidates vying to secure their party’s nomination for the November US presidentia(...)

US Republican presidential candidate Donald Trump: polls put the party frontrunner ahead in Alabama and Oklahoma. Photograph: Reuters

Billionaire Donald Trump has been heavily criticised for refusing to repudiate an endorsement from racist group the Ku Klux Klan. The 2012 Republica(...)

Pro-immigration reform Bill demonstrators from the Florida Immigrant Youth Network. Photograph: Joe Raedle/Getty Images

Passing the first major overhaul of US immigration laws in more than 25 years faces an uphill battle after conservative Republican opponents re(...)