First considered an underdog in the race, Republican Scott Brown won the Massachusetts Senate seat left behind by the late Edward Kennedy Tuesday night.

Senator-elect Brown defeated Democratic challenger Martha Coakley 52-47 percent with 96 percent of the precincts reporting in.

The election of the Republican breaks what is called the "filibuster-proof" majority for the Democrats in the United States Senate, which may jeopardize President Barack Obama's health care reform overhaul.

President Obama campaigned this weekend in the state for the Democratic candidate, but the efforts were unsuccessful.  Analysts are noting the historical significance of a Republican being elected as a senator in what is considered one of the "bluest" states in the country.

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FOX 25 Boston and FOX News contributed to this report.