Washington (CBS) - Gay rights and religion are at the heart of a simmering feud between Vice President Mike Pence -- and Pete Buttigieg, the Mayor of South Bend, Indiana.
Buttigieg, a Democratic presidential contender, has blasted Pence's cultural and religious conservatism; but, Buttigieg's tone toward the state's Republican former governor was more muted.
The two once had a cordial relationship. Buttigieg presented Pence with a South Bend promotional T-shirt. And at ceremonial events, Pence would lavish Buttigieg with praise.
Their interactions are now under scrutiny as Buttigieg's campaign has become a surprise hit.
As the openly gay mayor became a celebrated voice for LGBT equality, his rhetoric toward Pence has hardened.
Buttigieg has called Pence's religious conservatism a "fanatical" ideology. But Pence says Buttigieg "knows better."
On Sunday, Buttigieg is expected to formally launch his campaign for president.