In ways both subtle and blunt, Hillary Rodham Clinton’s campaign is sending a message to Vice President Joe Biden about his potential presidential campaign: This won’t be easy.

As Biden ponders a challenge to Clinton for the Democratic nomination, she has rolled out a string of high-profile endorsements in the early-voting contests of Iowa and South Carolina and scheduled an onslaught of fundraisers across the country in the effort to throw cold water on a possible Biden bid.

Donors who have publicly expressed support for a Biden run have been contacted by the Clinton team, according to donors and Democratic strategists who spoke on condition of anonymity because they were not authorized to discuss the private conversations. Even Clinton herself has made a few calls, they said, to express her disappointment.

While Clinton and her team speak warmly of Biden in public, they have taken steps to show their dominance over the party’s establishment and President Barack Obama’s political infrastructure in hopes of quietly discouraging the vice president from entering the race.

The effort comes as Clinton and the Democratic field of candidates prepare to address members of the Democratic National Committee on Friday during their summer meeting in Minneapolis. The night before her formal address, Clinton made her case in private briefings to attendees. Meanwhile, representatives from a super PAC backing Biden plan to woo delegates in his absence.

“I have great deal of admiration and affection for him,” Clinton said of Biden during a stop in Iowa on Wednesday. “I think he has to make what is a very difficult decision for himself and his family. He should have the space and the opportunity to decide what he wants to do.”

While Biden considered his options, Clinton’s team released a series of memos Thursday night that detailed their organizing work in early-voting states. “For months, we were the only campaign on either side of the aisle with offices and staff reaching out to voters,” wrote Clay Middleton, her state director in South Carolina. “This head start has provided an organizing advantage.”

Clinton’s campaign has taken other steps in South Carolina, where Biden has deep ties, to showcase her clout. She recently picked up the endorsements of two former governors, Jim Hodges and Dick Riley, the latter who served as education secretary during Bill Clinton’s administration. Her campaign’s chairman, John Podesta, appeared at an event in the state last week.

During a trip to the Iowa State Fair earlier this month, former Iowa Sen. Tom Harkin joined Clinton and endorsed her campaign. When she returned to Iowa this week, she was joined by Agriculture Secretary Tom Vilsack, a former Iowa governor who wrote in an op-ed in the Gazette of Cedar Rapids that he intended to caucus for her, “plain and simple.”

Clinton’s fundraising apparatus has extensive overlap with Biden’s, causing some awkwardness among their donors.

“I plan on supporting Secretary Clinton. She is the announced candidate,” said George Tsunis, a Long Island, New York, businessman and a top donor to Obama and Biden’s 2012 re-election campaign. “If the vice president were to announce his candidacy and run, I would be supporting the vice president.”

Clinton’s campaign, however, is not leaving an opening in fundraising, lining up about three-dozen events in September after the Labor Day holiday. The stops include Atlanta; Baton Rouge, Louisiana; Cincinnati; Dallas; Little Rock, Arkansas; Milwaukee; New York; Port Elizabeth, Maine; and Washington, D.C.

Some of the events will be hosted by leading donors to Obama and Biden’s campaigns, including New Jersey public relations executive Michael Kempner, Dallas attorney Marc Stanley, Washington money management executive Frank White Jr., and Rep. Don Beyer, D-Va., who previously served as Obama’s ambassador to Switzerland.

In Chicago, Clinton is scheduled to attend fundraisers on Sept. 17 hosted by two longtime Obama supporters, attorney Joseph Power and businessman Michael Polsky.

While her husband presides over the annual Clinton Global Initiative meeting in New York in late September, Clinton will raise money at seven fundraisers planned in Los Angeles and San Francisco. Following her West Coast swing, she will tap into the network of country music stars Faith Hill and Tim McGraw at a Nashville fundraiser on Sept. 29.

Those advocating for a Biden run say they’ll be able to build a vibrant primary organization and have already solicited commitments from a number of Clinton backers who say they are ready to switch sides.

“They don’t want to put their neck out unless they know Biden is in this,” said Jon Cooper, finance chairman of the Draft Biden super PAC, and a top Obama fundraiser. “But I have no doubt he’ll be able to put together a national fundraising infrastructure in place overnight.” He estimated the PAC would raise as much as $3 million over the next few weeks.

Asked about the possibility of Biden running, House Democratic leader Nancy Pelosi, D-Calif., told the San Francisco Chronicle on Wednesday, “I just don’t know. I just don’t know.”

She added: “I think there’s a lot of excitement in the country to have the first woman president of the United States. … We want to win. We have to win.”

(AP)