Sen. Claire McCaskillClaire McCaskillSenators question need for HHS cyber office Overnight Cybersecurity: Obama DHS chief defends Russian hack response | Trump huddles on grid security | Lawmakers warned about cyber threat to election systems We must protect our most vulnerable from financial fraudsters MORE (D-Mo.) pushed back on recent questions about whether former Secretary of State Hillary ClintonHillary Rodham ClintonJuan Williams: Trump refills the swamp Pelosi: Trump insisted he won popular vote in our first meeting Are Democrats trying to pin the blame for their own sins on Russia? MORE’s health should keep her from running in the 2016 presidential election.

“She knows how to ignore all the cheap shots and stay focused on the American people,” McCaskill said of Clinton during an appearance on NBC’s “Meet the Press” on Sunday.

Last week, Republican strategist Karl Rove questioned whether Clinton’s 2012 head injury should play a role in her decision to run for president.

McCaskill called Rove’s questions a “cheap political shot.”

“I think Karl Rove is struggling to be relevant” and “trying to be part of the conversation,” she said.

When asked about her support for President Obama during the 2008 Democratic primary, McCaskill said she had to make a “very tough choice” between “two amazing candidates."

Since that election, Clinton has served as secretary of State, which has “enhanced her resume,” McCaskill said.

“It’s her time, and I’m excited to try to be a part of it.”