(CNN) Rep.-elect Alexandria Ocasio-Cortez on Saturday responded to outgoing Sen. Claire McCaskill on Twitter after the Missouri Democrat referred to the incoming congresswoman as "a bright shiny new object" earlier this week.

"Not sure why fmr Sen. McCaskill keeps going on TV to call me a 'thing' and 'shiny object,' but it's pretty disappointing," Ocasio-Cortez, a Democrat from New York, wrote on Twitter.

"McCaskill promised she'd '100% back Trump up' on his anti-immigrant rhetoric & lost. In MO, almost all progressive ballot issues won," her tweet continued.

Not sure why fmr Sen. McCaskill keeps going on TV to call me a "thing" and "shiny object," but it's pretty disappointing. McCaskill promised she'd "100% back Trump up" on his anti-immigrant rhetoric & lost. In MO, almost all progressive ballot issues won. https://t.co/53qKvnr8KG

McCaskill lost her seat this past November while running for her third term in Missouri.

"I don't know her," McCaskill told CNN earlier this week when asked if she'd consider Ocasio-Cortez a "crazy Democrat" like the ones she decried on the campaign trail. "I'm a little confused why she's the thing. But it's a good example of what I'm talking about -- a bright shiny new object, came out of nowhere and surprised people when she beat a very experienced congressman."

"And so she's now talked about a lot," McCaskill added. "I'm not sure what she's done yet to generate that kind of enthusiasm, but I wish her well. I hope she hangs the moon. But I hope she also realizes that the parts of the country that are rejecting the Democratic Party, like a whole lot of white working class voters, need to hear about how their work is going to be respected, and the dignity of their jobs, and how we can really stick to issues that we can actually accomplish something on."

McCaskill concluded, "The rhetoric is cheap. Getting results is a lot harder."

Ocasio-Cortez continued to tweet about McCaskill later Saturday, writing: "I'm also not sure why McCaskill is covering for the GOP by saying they 'secretly think Trump is nuts.'

"Nobody cares," Ocasio-Cortez wrote. "Trump is melting down our institutions and inciting division between people. At any time GOP could have checked him and choose not to. They're accomplices."