For the second time this week, a major national poll shows Sen. Hillary Clinton widening her lead over Sen. Barack Obama.

A new Gallup poll taken March 14-18 gives Clinton a 49 to 42 percent lead–what Reuters is calling this morning, “a significant lead.” There is a margin of error of 3 points on this one.

Many will point out that what really matters is who has the most pledged delegates and superdelegates in their pocket come Democratic convention time this summer in Denver. That is certainly the case.

But, there are many unpledged and undecided superdelgates, or Clinton superdelegates thinking about going over to the Obama camp.

So, the importance of poll results such as these is that it may give possible defectors pause and may help convince undecided superdelgates that Clinton has a better chance to win a general election in November than does Obama.

That speech

It is way too early to tell just how effective Obama’s speech on race relations will impact the outcome of this contest. Already, more people have seen his speech on YouTube replays than anywhere else. What we don’t know is what all those people think of the speech, though there are some indications it went over well, especially at universities where Obama’s support is the strongest.

Setbacks for Hillary

Clinton has been hoping for new primaries in Michigan and Florida. So far, neither appears likely, increasing the need for some sort of deal to be struck behind the scenes-and ,yes, that is how this is likely to go down-to unite the party.