In fact, one irony is that yesterday was the anniversary of SuperTuesday in 2004. Leading up to SuperTuesday, Kerry had won 14 of 16 contests and was ahead by double digits in polls for SuperTuesday in all states except Vermont, where there was a movement to honor their favorite son, who was already out of the race.
There was NO looking for a non-Kerry. No view that he was outside the political mainstream in his party. In addition, he won those early states by retail politics. He was not the media favorite - even up to SuperTuesday. He obviously connected with voters. In addition, in the debates after Iowa, he was very Presidential batting off the attacks (normal because he was the front runner) easily and with humor and grace. It was quickly obvious that he was the best man on the stage. He had none of the thin skinned, barely hidden anger of Mitt Romney and none of the pettiness. In addition, Kerry did not spend close to $30 million on ads to destroy the rest of the field.
In fact, no open seat - in either party - was won as easily as Kerry won that nomination. It should also be noted that the meme that Kerry could not connect was mostly pushed by Democrats really preferring a 2008 reinstatement of their wing of the party. The fact though is that the 1992 nomination was a drawn out affair where Clinton was not the defacto nominee until June. Even that nomination run was not as convoluted, nasty and splintered as Romney's run. Romney's likely eventual win - fueled by millions in ads and the fact that he really has some pretty pathetic opponents - is as different as can be.
As to how they act toward people, I can imagine Romney calculating what would be in it for him before jumping in to save another person - something Kerry did several times. Better yet, the difference can be encapsulated in the stories of their kids. Kerry saved a poor drowning hamster (saving his little daughters from heartbreak), Mitt left the dog on the roof after it got sick and he had to clean the dog and the car to continue a 12 hour drive. Both are likely off the edge of a typical, normal response - to one's credit and the other's shame.