Most politicians have a political hero. Someone they look up to. Someone they wish they were half as good as.

Mine died 50 years ago this week. Murdered in a kitchen in a Californian hotel.

His dad called him a runt. His enemies called him ruthless. His brother called him Black Robert. We know him as Bobby.

The big picture: America says goodbye to Robert F Kennedy Read more

When he died so did the dream of Camelot restored, of another Kennedy in the White House. But Bobby wasn’t just another Kennedy. He was different from his famous brother.

For a start, he was shorter. But he was also tougher. Jack wrote a book about political courage. Bobby had it in spades. He took on everyone from Jimmy Hoffa to the mafia to white segregationists.

He also had a clearer moral compass than his older brother. When the world was on the brink of nuclear war for 13 days in October 1962, it was Bobby who convinced his brother not to bomb Cuba. With the memories of Pearl Harbour still fresh, he told JFK that America didn’t launch sneak attacks. The president took his advice and it probably averted a nuclear war. It was also Bobby who urged him to act on civil rights.

When his brother died, Bobby could have crawled up in a ball, never to be seen again. But he didn’t do that. Instead he used his fame and his name to shine a light on the darkest parts of America. On poverty and prejudice. On children dying of hunger in the richest country in the world. On the plight of migrant farm workers who picked but didn’t share in the national bounty and on what he called “a national disgrace” – the desperate deprivation endured by Native Americans.

At a time when America was tearing itself apart over a war it was losing in Vietnam and black and white Americans were fighting in the streets at home, Bobby Kennedy also tried to bring people together. If you haven’t seen it, watch the speech he made in Indianapolis on the night Martin Luther King died. No other white man could have made that speech. That night, fires burned in more than 60 cities across America, but Indianapolis was quiet.

Like any politician, he made mistakes. A big one was the decision he made when he was attorney general to tap Martin Luther King’s phone. He also admitted that the war he tried to end in Vietnam, he had also helped to start.

1968: the year that changed America Read more

And, like most politicians, he was ambitious – but he was ambitious with a purpose.

In South Africa in 1966, in the depths of apartheid, he told a group of university students: “Each time a man stands up for an ideal, or acts to improve the lot of others, or strikes out against injustice, he sends forth a tiny ripple of hope.”

That pretty much sums up Bobby Kennedy. He believed change starts with the actions of a single person and that if enough people do the same thing, they can bend history.

The world he hoped for isn’t here. Apartheid has gone, but poverty and prejudice are still here. The divide between rich and poor and black and white still exists – and not just in America. That doesn’t mean he was wrong. It just means we need to try harder.

We will never know what would have happened if Bobby Kennedy hadn’t walked through that kitchen 50 years ago, whether he would have won the Democratic nomination, whether he would have become president or even whether he would have been any good.

But I do know we need more people like Bobby Kennedy. Not just in politics. Everywhere. More people trying to bring us together. More people willing to act to improve the lives of others. More people seeking what Lord Tennyson called “a newer world”. More tiny ripples of hope.

• Jason Clare MP, member for Blaxland, is shadow minister for trade and investment, and shadow minister for resources and northern Australia