If you weren't paying attention, you might think that the late Senator Bobby Kennedy was running for president. His name comes up so often in references to his speeches or his ideology, that it hardly seems possible that he was making his run for the White House 40 years ago.

There are some similarities between Senator Barack Obama and Bobby Kennedy. Obama's ability to move people emotionally is the most obvious. But some of the comparisons are a bit lavish.

Kennedy was not a terribly deft politician. At least some of his celebrity came from the Kennedy name and his relationship to his brother, President John Kennedy.

Bobby seemed to act more out of instinct. It appeared as if he took pleasure in rocking the boat. And the public relished his crusader persona - taking on organized crime and Jimmy Hoffa.

There are few politicians on the national scene today with that kind of risk-taking mindset. But it's not that some of today's politicians are reminiscent of Kennedy. It's the striking similarity between the two periods of time.

By 1967, President Johnson had taken the US deep into the Vietnam War. The conflict in Southeast Asia had become an American conflict. And much like Iraq has become what some experts call a proxy war with Iran, the US was building up to a confrontation with Communist China.

At a time when it was dangerous to do so, Kennedy spoke about the immorality of the Vietnam War, and the deaths of thousands of innocent civilians. It was a message that resonated, particularly with young people.

And at home, he talked about a society that had become indifferent to poverty, at a time when the economy was beginning to show eerily familiar signs of strain. After eight years of George W. Bush, the growing gap between the rich and the poor makes the idea of eliminating poverty seem quaint and provincial.

But RFK's oldest daughter, Kathleen Kennedy Townsend, speaking on C-SPAN, said her father's most valuable contribution may have been his ability to broaden political debate beyond the obvious.

If Kennedy were alive today, you can be sure that we would be talking about more than abortion, stem-cell research, and gay marriage.