WASHINGTON ― Sen. Bernie Sanders (I-Vt.) is planning a national tour to give a boost to progressive Democratic candidates and energize activists in areas of the country that the party has long neglected, sources familiar with the planning told The Huffington Post. He will be joined on the road by prominent Democratic Party officials, including Democratic National Committee Chair Tom Perez.

Details of the tour are still being worked out, but Sanders, an independent who caucuses with Democrats, would have no shortage of potential whistle stops.

The focus will be on areas that lean Republican, but shouldn’t, Sanders said.

“The idea that we have a major political party today which has essentially given up on half of the country is beyond absurd. It is pathetic, because many of those states are some of the states in the most economic distress,” Sanders told HuffPost in an interview. “People who are living in impoverished states, whether it’s Mississippi or Alabama or South Carolina, states all over this country ― West Virginia ― states that are really hurting, should not be voting for right-wing Republicans to lead them, who are much more concerned about the interests of the wealthy and the powerful than ordinary people in their states.”

That Perez is taking to the road with Sanders suggests that the progressive wing’s fight to take over the DNC was not in vain, even if Sanders’ preferred candidate, Rep. Keith Ellison (D-Minn.), came up short. Sanders, a democratic socialist, nearly won the Democratic primary in 2016.

“You can ask whether you think two or three years ago the chairman ― the chairperson ― of the Democratic Party would have been talking about some of the same issues we’re talking about. Of course we’ve made progress,” Sanders said. “Look, Keith lost. But let’s remember, Keith lost a vote within the Democratic establishment. That’s no great secret. And he almost won that. So I think what Tom Perez understands, appropriately so, Tom wants to defeat Trump, Tom wants to see the Democratic Party grow. He understands ... the future of the Democratic Party is grassroots politics, it is talking to working people, it is involving young people in the political process.”

Sanders said that the tour is focused far more on grassroots party-building than on elections, but he will visit Omaha to try to boost a Democratic mayor there, and may go to Montana, where a populist Democrat is running in a House election.

Special elections across the country that were initially presumed to be easy Republican wins are turning into fierce contests. In suburban Atlanta, Georgia, Democrat Jon Ossoff is competitive in a race to replace Health and Human Services Secretary Tom Price, with Republicans pouring millions of dollars into a race they thought was in the bag.

In Montana, Democrat Rob Quist, a populist bluegrass legend, is up against a tech mogul from New Jersey in what could wind up being a close race, even though national Democrats so far have been staying clear of it. The lack of involvement in the race suggests Washington Democrats don’t believe the Montana race is winnable, but a survey conducted in March by Global Strategy Group, obtained by The Huffington Post, finds that independents widely favor Quist. It also found that when voters learn positive information about both Quist and his opponent, the race becomes a tie. (Before that, Quist trails by roughly 10.)

“If it works out, we’d love to go to Montana and help Quist in his race,” said Sanders. “My impression is he’s a very strong candidate who stands up for working people, understands that we need a government that represents all of us and not the 1 percent. So if we can be of help to Quist, happy to do that as well.”

Even in Wichita, Kansas, home of Koch Industries, the race to replace CIA Director Mike Pompeo is shaping up to be a real contest, with Republicans dropping a hefty amount of cash in a last-minute, panicked move to shore up the seat.

Democrats in South Carolina are also making a play for the vacated seat of Mick Mulvaney, though it hasn’t received national attention and is the longest shot of the bunch.

Democrats are likely to be able to widely expand the field of winnable seats in November 2018, if recent local special elections are an indication of enthusiasm among Democrats and a lack of it among Republicans. For Sanders, political organizing means more than coming out once every two or four years to vote. He has long talked about building enduring organizing networks that can be mobilized not just on behalf of party politics, but also for specific local, national or global issues.

Sanders said that he has not made up his mind about a presidential bid in 2020, but nobody should interpret his tour as paving the way for one.

“Does it shock you to know that my goal really is to increase political participation in this country, to get working people to stand up? Is that not a good enough goal?” he said. “If you’re interpreting this as some kind of presidential effort, that’s total nonsense. I certainly have not made any decisions about it. This is a goal to try to do what we can to bring the American people together to take on Donald Trump to transform our political system, to raise political consciousness.”

This story was updated to include comments from Sanders.