Haley -- a first-term Republican who is running for re-election in 2014 -- posted the picture Thursday of a 9 mm Beretta PX4 Storm pistol she said her husband, Michael, gave her.
"Our family had a wonderful Christmas together! I must have been good Santa gave me a Beretta PX4 Storm," she wrote.
By Friday morning, the post had attracted nearly 18,000 likes and more than 2,100 comments -- some critical but many supportive.
Phil Bailey, political director of the South Carolina Senate Democratic Caucus, posted photos on Twitter Friday showing him and Haley's main Democratic rival in 2014, state Sen. Vincent Sheheen, with shotguns at a shooting range.
"@vincentsheheen & me after he kicked my ass shooting skeet with his shotgun he's had longer than I've been living," Bailey tweeted.
Amanda Loveday, executive director of the South Carolina Democratic Party, said on Twitter: "Everything is about politics with [Haley]. Everything," the State of Columbia reported.
Sheheen's campaign manager, Andrew Whelan, tried to stay out the crossfire, saying, "We hope everyone had a Merry Christmas and happy holiday season with family and friends."