To Mitt Romney's eternal embarrassment, Donald Trump received 45,000 more votes in the Massachusetts Republican Primary in 2016 than Romney did in the 2012 primary in his own state in which he'd served as Governor

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2016 and 2012 Massachusetts Republican Primary results:

March 1, 2016: Trump: 311,313

March 6, 2012: Romney: 266,313

Sources: 

2012: CNN: "REPUBLICAN PRIMARY March 6, 2012"
 
"Semi-open primary: Registered party members may only vote in their own party's primary, but independents may vote in either contest."


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2016:  CNN Election Center: Massachusetts primary March 1, 2016, updated March 2, 2016

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Romney was Governor of Massachusetts from Jan. 2, 2003 to Jan. 4, 2007.

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