Santorum a winner but he still trails Romney

Although the victory gives Mr Santorum bragging rights, it does not change the overall dynamics of the race.

The former Pennsylvania senator still dramatically lags behind Mr Romney in the hunt for delegates to the Republican’s summertime nominating convention.

Even so, Mr Santorum’s win underscores a pattern in the drawn-out race.

The under-funded under-dog has tended to win in Bible Belt states that include Tennessee, Mississippi and Alabama. Romney – a deep-pocketed, highly organised former Massachusetts governor – has persistently struggled in such heavily conservative regions.

Neither candidate was in the state as Louisiana Republicans weighed in. Nor was former House Speaker Newt Gingrich, who was trailing in Louisiana.