Left-wing Democratic leaders Sen. Bernie Sanders, I-Vt., and Democratic National Committee chair candidate Rep. Keith Ellison, D-Minn., are seeking to rebuild a party that has been left in shambles by the Obama presidency.

The Democrats have lost majorities in the House and Senate and been obliterated by the Republicans at the state and local level since Obama assumed office in 2009. In a speech this week to progressive activists at a rally for Ellison's candidacy to lead the Democratic National Committee, Ellison and Sanders both said the party needed new leadership and noted that it had declined during recent years.

"Clearly, whatever the leadership of the Democratic Party has been doing over the last many years has failed, and we need fundamental change," Sanders said.

Ellison has as his main competition is Labor Secretary Tom Perez, who joined the campaign on Thursday.

During his remarks to the progressive audience, Ellison acknowledged the decimation of the Democratic Party, citing the exact period Obama has been in office.

"I know some folks don't want to hear it, but since 2008, Democrats have lost 935 legislative seats and Republicans now control two-thirds of governors' offices," Ellison said. "It has devastated us."

Obama is a historic figure, beloved across the Democratic Party.

He is the first black president, and the first Democratic presidential candidate to win more than 50 percent of the vote, back to back, since Franklin Delano Roosevelt. Obama presided over recovery from the Great Recession and accomplished the Democrats' generational dream of enacting national healthcare reform.

He is poised to exit the White House with high approval ratings, but for much of his presidency less than half the country liked the job he was doing, and several of his policies were unpopular, like Obamacare. The problem may have rubbed off on others.

Over Obama's eight years, Democrats went from controlling 28 governor's mansions to 18; they went from controlling 25 state legislatures to 12; they went from controlling 60 Senate seats to 48; and from controlling 257 House seats to 194.

And of course, they lost the White House too.

Sanders built a constituency inside the party through waging a vigorous challenge to Hillary Clinton in the 2016 Democratic presidential primary. In the race for DNC chairman, Ellison represents the Sanders, anti-establishment, wing of the party.

But establishment forces also are pre-occupied with the monumental rebuilding effort the party faces ahead of the 2018 and 2020 elections. Democrats supporting Perez are hesitant to openly criticize Ellison. But subtly, their knock on him is that he's not up to such a big job.

They question whether Ellison is capable of raising the resources the DNC needs to finance massive amount of political activity required to get the party back on its feet and whether he has the executive skills to manage such an undertaking.

These are the issues that are likely to play a deciding role in the campaign, said Perez backers Gilberto Hinojosa, the Texas Democratic chairman, since, at least in his view, the candidates tend to share the same progressive philosophy.

The chairman race is about "who they believe would be the kind of chair that can administer this large organization called the United States Democratic Party — not just what's in Washington, D.C., but working on a state and local level throughout America," he said, in an interview with the Washington Examiner.

There are about 450 voting members of the DNC. The chairman election is likely to occur in February or March. Before then, the competitors are scheduled to square off in public forums in Baltimore, Detroit, Houston and Phoenix.

This story was edited to clarify that Sanders' and Ellison's remarks were made in the context of Ellison's bid to lead the DNC.