WATCH: US Senator describes Trump as “thin-skinned, racist bully” in scathing attack

Elizabeth Warren says the Republican candidate “serves no one but himself”

Elizabeth Warren, Donald Trump, criticism, attack, Republican candidate, Senator, speech

US Senator Elizabeth Warren, D-Mass., speaks at the American Constitution Society for Law and Policy 2016 National Convention in Washington | Image: Nick Wass / AP/Press Association Images

A US Senator from Massachusetts has launched a stinging attack on Donald Trump, before endorsing Hillary Clinton for US president.

Senator Elizabeth Warren called the Republican candidate a "racist bully" who has "never risked anything for anyone and who serves no one but himself."

She said he “chose racism as his weapon" – alluding to his criticism of US Judge Gonzalo Curiel.

In an interview with the Wall Street Journal, Mr Trump claimed the judge could not fairly preside over cases relating to him because of his “Mexican heritage.”

Judge Curiel is from Indiana and his parents are Mexican immigrants.

The judge is presiding over a pair of cases which allege Trump University duped them into paying tens of thousands of dollars on the belief they would be trained to learn his real estate strategies.

Mr Trump denies the allegations.

 “Trump is criticising Judge Curiel for following the law, instead of bending it to suit the financial interest of one wealthy, and oh so fragile, defendant”, Senator Warren told the American Constitution Society in Washington.

“Trump is picking on someone who is ethically bound not to defend himself – exactly what you would expect from a thin-skinned, racist bully”.

She says Trump should be “ashamed for using the megaphone of a presidential campaign to attack a judge’s character and integrity, simply because you think you have some God-given right to steal people’s money and get away with it”.

“You shame yourself and you shame this great country”.

“Donald Trump is a loud, nasty, thin-skinned fraud who has never risked anything for anyone - and who serves no one but himself”.

“And we will not allow a small, insecure thin-skinned wannabe tyrant or his allies in the Senate to destroy the rule of the law in the United States of America,” she added.

Later, endorsing Trump’s Democratic rival Hillary Clinton, Senator Warren told MSNBC: "I'm ready. I am ready to get in this fight and work my heart out for Hillary Clinton to become the next president of the United States - and to make sure that Donald Trump never gets any place close to the White House.”

Watch the full speech here