While the Republicans have tried several times over the years to influence the outcome of Democratic primaries to suit their wishes, I think a coordinated effort of this magnitude has never been attempted.
Which begs the question:
Why do the Republicans love Hillary?
Since early January, right-wing talkers like Rush Limbaugh, Ann Coulter and Sean Hannity have encouraged Republican voters to cross party lines to vote for Clinton, or even in the case of states like Pennsylvania, which doesn't have an "open" primary, they've implored their target audience to switch party registration so they can vote for Hillary!
Just one day after Clinton's win in the Pennsylvania primary, the North Carolina GOP has released an anti-Obama television ad, featuring the words of scandalous Obama ex-pastor Jeremiah Wright. This ad is so inflammatory that even McCain felt compelled to speak out against it. Which, of course, has the added benefit of further publicizing the ad while making St. John look like a swell guy.
Which the NC GOP will ignore, and everyone gets to see the ad anyway!
But why bother wasting precious Republican dollars on an ad that will only have minimal effect on McCain's efforts, but may directly impact the Democratic primary with the hope that it will take votes AWAY from Barack Obama?
The only reason for this that I can see is that the Republicans are chomping at the bit to face Hillary in November. They are convinced they can much more easily defeat Clinton in the general election. The GOP knows Clinton has loads of baggage, which having spent so many years in Washington is very easy to accumulate.
They feel that their DC insider can beat another DC insider.
Barack Obama terrifies the GOP exactly because he's NOT the same as McCain. While Clinton is currently enjoying a post-win bump in fund raising, Obama consistantly draws an insane amount of support from regular people; just look at the crowds you see at any Obama rally. He outdraws Clinton every single time, because he generates hope and excitement. The Republicans can't possibly cope with that kind of popularity, so they're betting they'll do well against the one Democratic candidate who most closely resembles theirs.
This is why the GOP loves it some Hillary.