Vermont Sen. Bernie Sanders is pressing ahead with a potential White House bid, returning to Iowa and New Hampshire this week for more events in the early presidential states.

He’ll be in Davenport, Iowa, on Saturday for a meeting with local activists on the economy, before heading to Iowa City on Sunday to headline the Johnson County Democratic Party barbecue. That night, he keynotes a meeting of Iowa Citizen Action Network in Coralville.

On Friday, he heads to New Hampshire for a town hall meeting with students at the University of New Hampshire in Durham.

Close video Senator Bernie Sanders heads to Iowa Sen. Bernie Sanders traveled to Iowa, testing the waters in a state crucial for a potential Presidential run. Ed Schultz and Sen. Sanders discuss his time on the ground in Iowa. share tweet email Embed

Sanders, an independent who caucuses with Democrats, is openly considering a long-shot presidential run. In private meetings with prominent progressive activists this summer, the senator’s advisers said he is leaning heavily towards running, according to people familiar with the meetings.

The aides said he’s most likely to run for president as a Democrat, with a small chance of him running as a independent, and an equally small chance of him staying out of 2016 entirely.

While most dismiss Sanders’ chances, even some supporting Hillary Clinton are concerned he could find unexpected success against the more establishment Democrat.

“I have nightmares that someone like a Bernie Saunders will catch fire and cause trouble for Hillary Clinton. People sometimes ignore who the most electable candidate is and which candidate is best prepared to lead the country in favor of the fun of being a contrarian in the moment,” said one pro-Clinton Democratic operative, who asked to remain anonymous to speak candidly.

Bill Gluba, the mayor of Davenport and a longtime Iowa Democratic activist who got onboard early with Barack Obama in 2008, has met with Sanders this year and said there’s “a real hunger” among the grassroots for a candidate willing to take on Wall Street and the 1%.

“He’s about the only one really clearly speaking to the real issues,” said Gluba, who has not yet committed to anyone.

“Bernie’s already starting to get traction in Iowa,” the mayor continued, guessing that if the election were held today, Sanders could capture about a quarter of the vote. “This thing is wide open – you can say it isn’t, but just you wait.”

Last month in New Hampshire, the local chapters of the AFL-CIO and SEIU invited Sanders to headline their annual Labor Day Breakfast, where he got a warm reception from union members.

Clinton won that state in during her last presidential and is currently almost 50 percentage points ahead of her nearest competitor. In the most recent poll, from CNN/ORC, Sen. Elizabeth Warren comes in a distant second at 11%, Vice President Joe Biden follows at 8%, and then its Sanders at 7%.

That puts him ahead of Maryland Gov. Martin O’Malley, who is diligently laying the groundwork for a run, and within the margin of error for second. Warren, from nearby Massachusetts, has repeatedly said she is not running in 2016.

In Iowa, where Obama unexpectedly routed Clinton in the state’s kickoff caucuses in 2008, the situation is largely the same. The former secretary of state is a bit weaker in the Hawkeye State that she is in New Hampshire, but still overwhelming strong. Sanders gets 5% of support, according to the CNN/ORC poll.

Jerry Crawford, an Iowa Democratic powerbroker who was Hillary Clinton’s Midwest co-Chair in 2008 and is involved with the pro-Clinton Ready for Hillary super PAC, said he could see Sanders finding modest support in the state.

“In any caucus state, including Iowa, candidates on the philosophical fringes will still get plenty of support. The caucuses are made to order for those folks,” he told msnbc.

Another longtime Clinton aide compared a possible Sanders presidential bid to Jesse Jackson’s twin runs in the 1980s. jackson, who captured enough to support to credibly raise issue that were important to him, was never a real threat.

Former Vermont Gov. Howard Dean, who has worked with Sanders in their shared home state for years, and who run a left-leaning presidential campaign in 2008 fueled by the Democratic base, is backing Clinton.

But in a recent appearance on MSNBC’s Up! With Steve Kornacki, he added that Sanders would be a good challenger for Clinton. “He does not do dirty politics. He sticks to the issues, and the issues are important that he’s raising for the country, not just the Democratic Party,” the former Democratic Party chair said.