Story highlights Kaine says his critics are "right -- I am boring."

Kaine and Labor Secretary Tom Perez were on Sunday shows

Washington (CNN) Tim Kaine said Sunday he agrees with the most oft-cited criticism of him as a potential vice presidential candidate, saying that it's true, "I am boring."

The Virginia senator -- a former governor and Democratic National Committee chairman -- is among the Democrats reportedly on Hillary Clinton's short list of potential running mates.

The biggest criticism is that, compared to options like Massachusetts Sen. Elizabeth Warren, who could excite liberals, or Housing and Urban Development Secretary Julian Castro or California Rep. Xavier Becerra, who could attract Latino voters, Kaine -- who is fluent in Spanish himself -- is boring.

Asked on NBC's "Meet the Press" Sunday about those characterizations, Kaine didn't disagree.

"But boring is the fastest-growing demographic in this country," he said.

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