GREEN BAY, Wis. (AP) — Another victory in hand but still badly trailing rival Mitt Romney, Republican presidential hopeful Rick Santorum vowed to continue his campaign despite an increasingly steep climb to the nomination.

Santorum, buoyed by Saturday's win in Louisiana's primary that boosted his spirit but did not narrow the delegate gap, urged his supporters to stick with him even as much of the GOP establishment has coalesced around Romney's increasingly inevitable coronation. Even in the face of the political headwinds, the former Pennsylvania senator seemed unwilling to acknowledge it would take a dramatic change in momentum to deny Romney his turn as the GOP nominee.

"You don't believe, as the pundits have said, that this race is over. You didn't get the memo," said Santorum, who won bragging rights in an 11th nominating contest but did little to shift the dynamics of the drawn-out race. "We're still here. We're still fighting."

But it's going to be a tough fight, for sure.