Expect a huge dem dump from DeKalb County!

Perdue and Loeffler are toast after DeKalb and Chatham come in..

Keeps Georgia on my mind.  But I can wait until the final tallies are in.  
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I don't really know Georgia politics or the major local issues but I have a mostly serious Q. The current vote count (late night, Tuesday) is around:  

David Perdue   2,189,198
Jon Ossoff         2,187,329
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and
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Raphael Warnock    2,205,826
Kelly Loeffler       2,170,795
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If this was a STRICT PARTY LINE election, Perdue and Loeffler should have the same number of Rep votes and Warnock and Ossoff should have the same number of Dem votes.  But they don't. Why?
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Why did 2,189,198 - 2,170,795 = 18,403 vote for Perdue but not vote for Loeffler? Did they cross over and vote for Warnock? Do they just hate Loeffler or do they love Warnock just a little bit more?  
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It can be asked from the other side, as well. Why did 2,205,826 - 2,187,329 = 18,497 voters choose Warnock but whiff on Ossoff?  
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Are there major local or regional or singular issues that led even very Red or very Blue Georgians to split their Senator votes and support P but reject L? Or support W but reject O?  
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Depending on who are declared the winners, I think my statistical analysis could be grounds for a legal challenge of the outcome.  

or at least the explanation I heard last night on either CNN or MCNBC.  Loeffler is easier to beat because she's a newcomer and much less well known in GA than Purdue. The latter is the brother of "Sonny" Perdue, the former governor and also did some good locally getting storm relief to part of the state. So he has some support in that area from people who might otherwise have voted for Ossoff and DID vote for Warnock.
Made sense to me.