Well, McCain showed that he can win a Republican only primary. Interestingly exit polls showed that Romney actually got more votes from registered Republicans who identify themselves as Republicans. What put McCain over the top was registered Republicans who identify themselves as independents and Democrats. Many chose to register for the Repubican primary, since the Dem primary didn't count. This doesn't diminish the significance of the win, since in a national election one has to draw from all parties to win.
Gulliani's out and endorsing McCain. Romney made essentially the same speech he's made for the last couple of weeks. This is not a good tactic in today's instant media world. Repitition sounds like desperation. A possible positive trend for the Democrats is that the hard core conservative wing of the Republican party is looking far less influential than they'd like to be. When the right wing doesn't get its way, it gets cranky and sometimes chooses not to vote come the general election. This hurt Bush Sr. as well as Bob Dole.
For all the talk of McCain's lack of conservative credentials, he has put together an impressive team, including Jack Kemp and Phil Gramm, a couple of very capitalist foot-soldiers.
On the Democrat side, Hillary pulled a fast one. After avoiding campainging until after the vote, as agreed to by all the candidates due to DNC censure, she showed up in Florida immediately after the results were in to hold a victory rally, then played it up on TV. Ironically, the trend in the final days went to Obama. The race turned out much closer than predicted even though he didn't campaign there.
Edwards dropped out this morning. His endorsement may make news, but I'm not sure how much impact being endorsed by a losing candidate really has. Thompson's exit and endorsement of Romney did not put him over the top, even though the race was tied at the time.
In the end the Democrats will rally around their candidate. They tend to hate Republicans much more than each other. Republicans tend to be more divided. The right has some single issues that they just wont budge on. They'll sit on the sidelines and watch a socialist win before they vote for someone who might lean pro-choice or not be anti-gay marriage enough. If McCain wins the nomination, independents and cross-over Democrats will be a must for him. Where he will have an edge is on national security and budgetary policy. If'n I were advising any Republican I would say give the Dem some rope. Let them propose big spending programs from now until August, then start asking how they're going to pay for it all. If'n I were advising the Democrat, I'd say keep it vague and optimistic.