In a statement released by Kupchick's campaign, McKinney praised her preparation as a freshman legislator two years ago and said her small-business experience was "urgently needed" to address the state's high unemployment rate and its business climate.
"During her first term, Brenda hit the ground running," McKinney said. "Brenda built a reputation for straight talk, hard work and a willingness to work across party lines to solve problems."
A Fairfield Republican, McKinney said Kupchick is "clearly the best candidate in this race."
In a news release, Kupchick said she hopes to continue "working on the issues that matter to my constituents."
Kupchick is opposed by Democrat Sue Brand.