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At the end of every Little League game I played as a kid, we would always line up, shake our opponents hand, and tell each other that we played a "good game." Well, politics ain't beanbag, and it ain't Little League either, and some folks will continue to hold a grudge even after the contest is over.

After learning that he had lost the Florida GOP Gubernatorial nomination to millionaire Rick Scott, Florida Attorney General Bill McCollum delivered one last slam on his primary opponent Tuesday night. "No one could have anticipated the entrance of a multi-millionaire with a questionable past who shattered campaign spending records and spent more in four months than has ever been spent in a primary race here in Florida," McCollum said in a statement.

Usually concession statements are gracious affairs that urge supporters from both camps to put past struggles aside and work together to defeat the other party in November. Sometimes though, primary candidates break the unsaid protocol of unity.

When that happens, look out. "Dissension never helps a party's candidates," says Larry Sabato, director of the University of Virginia's Center for Politics, "It's a minus, and there's no way to dress up a pig and make it pretty." Sabato expects McCollum to come on board eventually, even if his support is less than enthusiastic.

It isn't the first time this cycle that a losing opponent has declined to endorse, or withheld an endorsement from their challenger.

Kentucky Lt. Gov. Dan Mongiardo (D) waited for weeks, after losing his party's nomination to run for the U.S. Senate seat, left vacant by retiring Sen. Jim Bunning, R-KY, to endorse his opponent. Mongiardo told the Louisville Courier-Journal shortly after his defeat that before making an endorsement for Democratic nominee Jack Conway, he would like to see him "being a leader, more independent and less handled." Mongiardo later jumped on board, though it hasn't helped Conway overtake Republican challenger Rand Paul's lead.

After Connecticut's August primary, former U.S. Rep. Rob Simmons, R-Conn., also refused to endorse his primary opponent, pro-wrestling mogul Linda McMahon. Shortly after his loss, Simmons told a Connecticut reporter that he would not "obstruct" McMahon's candidacy but that he's "never tried to play the role of party boss that delivers the vote." Connecticut Republicans have asked Simmons for a stronger endorsement, but he has so far stayed silent on the matter.

In all these cases party strategists on both sides of the aisle agree that the winner needs to be the one to reach out to bring the party together. "Divisions make it hard to exercise power," says Democratic strategist Simon Rosenberg. Noting that rallying the base will be essential to winning close races in November, GOPAC Chairman Frank Donatelli says that "it behooves the winner to put the party back together again."

Fox News' Elena Isella contributed to this report.

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