Former Democratic presidential candidate John Kerry, who has kept a relatively low profile since his loss in November to President Bush, returned to the public stage today with a combative speech on healthcare. The speech, delivered one year after his victory in the New Hampshire Democratic primary, sent a signal that the Massachusetts senator is keeping open the possibility of running again in the 2008 presidential election. "I must say I did have to travel a few more blocks than I had hoped to get here,'' Kerry said wryly as he began his remarks to healthcare advocates gathered in Washington's...