This chart is a composite of some 160 preference polls conducted over the last year. It demonstrates visually what so many of us have known is our gut: it's never really been much of a race between Hillary and Obama.
Check out the data.
For example, Obama's climb started back in October--some three months before the Iowa Caucuses. Observe how the trajectory of rise rocketed beginning in early December of '07. It was that momentum that explains his "surprising" triumph in the snowy plains of Iowa in early January.
So even though the media has tried to generate a horse-race between Hillary and Obama, the truth is that one never really materialized. The Hillary candidacy has been stalled from almost day one--kept aloft only by her superior name recognition, spin by her campaign, and the media's desire for a horse race.
Of the three Democratic competitors tracked by the polls, Edwards is the gelding that starts with a limp and is quickly scratched. Hillary is the mare who's only a trotter. And Obama is the thorough bred that forces a quicker pace, drafts, then turns it on in the backstretch and wins by a number of lengths.
Granted the primaries are not yet over and all sorts of things can happen to shake up the race between now and the primaries in Ohio, Texas, Vermont and Rhode Island. But then again, the chart does remind us that this race is really between a mare and a thoroughbred.