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U.S. Sen. Rand Paul got plenty of attention Saturday during the Fancy Farm Picnic in Western Kentucky.

But it wasn’t the good kind.

“Now, Rand Paul is busy,” Fancy Farm emcee Matt Jones told the crowd. “He has a presidential race to lose. He has to make sure to take care of that.”

Jones and others — Democrats, particularly — piled up on Paul all weekend.

With the Kentucky senator’s White House bid in the national news for its recent struggles, state Democrats are uniting behind the belief that he may also be vulnerable in his simultaneous effort to retain his Senate seat.

Most polls show Paul getting in the range of 5 percent of the vote in the crowded Republican presidential primary field. His fundraising efforts have been equally lackluster.

In a recent story, Politico reported that Paul’s aversion to seeking big campaign donations from wealthy contributors is part of what’s holding him back.

Stephen Voss, a political science professor at the University of Kentucky, said the biggest problem is Paul’s personality.

“It’s really hard to say what part of being a politician Rand Paul likes,” Voss said.

Paul’s supporters may appreciate that he doesn’t like to cozy up to billionaires for campaign cash—necessary interactions for a successful campaign, Voss said.

“Fundraising and support in the polls have a feedback loop,” Voss said. “When you do better in the polls, it’s easier to attract money. When you have the money to devote your attention to the right places, you rise in the polls.”

For the moment, Paul is stuck in a negative loop. And Kentucky Democrats are paying attention.

Paul appears to be focused on keeping his presidential bid afloat; he’ll be among the 10 Republican candidates scheduled to participate Thursday in the first debate of the 2016 presidential election season. But he may be leaving himself open for competition back home for his Senate seat.

Democratic Gov. Steve Beshear said Paul’s absence at Fancy Farm, one of the state’s centerpiece political events, was a misstep.

“I guess Sen. Paul has more important things he thinks and places he thinks he should be than here, but I thought he was running for the U.S. Senate next year,” Beshear told reporters this weekend. “If he is, he ought to be at Fancy Farm.”

While most statewide politicians gathered this weekend in the small Western Kentucky community, Paul made campaign stops in Iowa and Illinois.

Before Fancy Farm, veteran political commentator Al Cross said Paul’s absence from the picnic could provide an opening for Democratic state Auditor Adam Edelen — a potential Senate challenger — to criticize Paul without a rebuttal.

And that’s exactly what happened.

During his Fancy Farm speech, Edelen criticized Paul for a Senate filibuster aimed at curtailing the U.S. domestic surveillance program.

“We also prefer the speeches that Rand Paul gives at Fancy Farm than the ones he gives in the well of the U.S. Senate,” he told the rowdy crowd. “The difference being in Fancy Farm, Rand Paul is limited to five minutes, and his speeches don’t jeopardize the national security of this country.”

Edelen has not announced plans to challenge Paul, but his speech could be a sign of things to come.

Paul campaign spokeswoman Kelsey Cooper said the candidate has remained active in the Senate, working on issues ranging from “economic freedom zones” and disaster relief in the state.

“To suggest that Senator Paul, someone with nearly perfect attendance in the Senate, is anything but completely committed to the job he was elected to do is a blatant disregard for his strong record of defending and supporting the values and issues important to all Kentuckians,” Cooper said in an email.

Paul’s issues on the campaign trail could also jeopardize whether state Republicans will want to approve a presidential caucus next year so he can run for both the White House and U.S. Senate simultaneously. State GOP leaders are expected to vote on a plan later this month.