Former Iowa Lt. Gov. Patty Judge has launched a campaign for the Democratic nomination to run against Republican U.S. Senator Charles Grassley, making Supreme Court nomination hearings a key issue.

She says Grassley "is acting like someone who has been in Washington for far too long."

Judge, Iowa's first woman to serve as agriculture secretary, served four years as lieutenant governor with Democrat Chet Culver who was defeated in 2010 after one term.

Judge's announcement Friday creates a Democratic primary with state Sen. Rob Hogg and two other Democrats.

The 82-year-old Grassley has refused to hold Supreme Court nominee hearings in the Senate Judiciary Committee he chairs, a position Democrats believe weakens him politically.

Judge says he's promoting obstructionism.

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The National Republican Senatorial Committee says Judge is an out-of-touch liberal.