Former Iowa senator Harkin endorses Clinton

Former U.S. Sen. Tom Harkin, a longtime force in Iowa Democratic politics, is endorsing Hillary Clinton for the presidency, saying they have 'many of the same deeply held beliefs.”

Harkin, who retired last year after 30 years in the Senate, gave Clinton the nod in an op-ed in the Des Moines Register.

'As Democrats, we're fortunate to have a slate of candidates that are all fine individuals, but we need a fighter who has a record of getting things done and the vision for the future that will build on the progress we've made. For my wife, Ruth and I, that candidate is Hillary Clinton,” Harkin wrote.

The ex-senator cited Clinton's time in the U.S. Senate and as Secretary of State, saying she'd advanced women's rights and economic opportunity in both roles.

'Hillary has never forgotten who she is fighting for,” Harkin added.

Clinton appeared along with her husband at Harkin's last Steak Fry fundraiser last year.

The endorsement came on the day of the 2015 Iowa Wing Ding, a major Democratic event sponsored by more than two dozen county parties in Clear Lake.

Polls have said that Clinton holds a wide lead in Iowa, but she is facing a challenge especially from Sen. Bernie Sanders, of Vermont, who is drawing large crowds across the country and showing surprising strength in some early polls.

A poll in New Hampshire earlier this week said Sanders is leading there.

Also in the race are former Maryland Gov. Martin O'Malley, ex-Sen. Jim Webb and former Rhode Island Gov. Lincoln Chafee.

There also have been reports that Vice President Joe Biden has been asking allies for advice and that people close to him have made recent inquiries into early states, including Iowa.