"I'm having a physical reaction to the T-shirts," Amanda Carpenter, a speech writer for Sen. Jim DeMint (R-SC) tweeted tonight. "I'm tearing up. This feels wrong."
(The tweet has since been deleted.)
Other conservatives on Twitter shared in the sentiment. Some have already speculated the shirts were paid for with taxpayer dollars.
[TPM SLIDESHOW: Tucson Heroes: Arizonans Shine In Face Of Tragedy]
Michelle Malkin had earlier raised a rukus about the event's logo on her blog.
"Isn't the churning of the instant messaging machine a bit, well, unseemly?" she wrote. "Can't the Democrat political stage managers give it a break just once?"
Right-wing media star Tammy Bruce had some of the harshest attacks on the event and the crowd here in Tucson. She likened the event to the 2002 funeral for Sen. Paul Wellstone (D-MN), which conservatives at the time claimed was unfairly turned into a political rally by Wellstone's supporters.
"Massacre Rally Theatre is a complete abomination. Absolutely obscene," Bruce tweeted Wednesday. "Clinton should be happy, no longer will 'Wellstone' be the benchmark."
Additional reporting by Ryan J. Reilly.
This post has been updated since it was first published.