When the presidential campaign of Senator Clinton announced that veteran Democratic aide Burns Strider had signed on last month, the new staffer’s duties were widely described as “evangelical outreach.” Mr. Strider had a similar role with Rep. James Clyburn of South Carolina and the House Democratic Caucus, coordinating outreach to religious groups.

But Mr. Strider also has recent experience helping a liberal female lawmaker quash the political aspirations of a young, up-and-coming African American in a Democratic primary. As Senator Clinton contemplates the rapidly rising star Senator Obama of Illinois and his recent interest in a presidential bid, the former first lady may wish to review Mr. Strider’s most recent experience with political hardball.

The battleground was Mississippi’s second congressional district, encompassing Jackson and rural parts of the Mississippi Delta, in the most recent election cycle. The state’s longest-serving and most influential African-American lawmaker, Rep. Bennie Thompson, had won re-election, but by a bit less than expected, in two straight cycles. A state legislator, Chuck Espy — the nephew of former congressman and Clinton administration Secretary of Agriculture Mike Espy — made comments indicating interest in a primary challenge in 2006.

In early 2005, Mr. Thompson sought the help of the House minority leader at the time, Rep. Nancy Pelosi of California. A memo by a Pelosi staffer detailed how she and the Democratic establishment could squash Mr. Espy’s chances before his campaign gained any momentum. While the author of the memo was deleted from the copy obtained by the press, the Pelosi staffer most familiar with Mississippi politics was her senior aide, Mr. Strider, a native of Grenada County in that district.

The memo suggested Ms. Pelosi reach out to a former congressman, Tony Coelho, a mentor and close friend of Mike Espy, and seek his help in persuading the senior Mr. Espy to put the kibosh on his nephew’s potential bid.

Mr. Coelho later confirmed that Ms. Pelosi had called him but declined to comment further. But Mike Espy told the Mississippi and Capitol Hill press that he had been contacted by Mr. Coelho, whom he described as “disturbed” by the call he received from Ms. Pelosi. Mr. Espy said he had seen the memo and was “disappointed” and that Ms. Pelosi’s actions had made both he and Mr. Coelho more determined to support a primary challenge. The memo also detailed efforts by the Democratic Congressional Campaign Committee to punish a Washington-based consulting firm, Strother-Duffy-Strother, for signing on with the junior Mr. Espy at the start of 2005. The firm had worked with the DCCC in earlier cycles. According to the memo, DCCC Executive Director John Lapp had made clear that the committee would not provide any contracts to a firm seeking to unseat an incumbent and that candidates in other states would be strongly discouraged from working with Strother-Duffy-Strother.

In addition, the memo indicated that Ms. Pelosi would discourage Democratic-leaning organizations from meeting with Mr. Espy when he came to Washington.

A defeat of Mr. Thompson was unlikely but not unthinkable. A few years earlier, young African-American Democratic lawmakers had knocked off two of the “old guard” members of the Congressional Black Caucus, Reps. Earl Hilliard, a Democrat of Alabama, and Cynthia McKinney, a Democrat of Georgia. Mr. Espy’s insurgent bid appeared to be cut from the same cloth.

In January 2006, Strother-Duffy- Strother and Mr. Espy agreed to end their business relationship, and Mr. Espy hired Mississippi-based consultants who had worked with his uncle. But as the year progressed, it became clear that Mr. Espy’s fund-raising would not meet expectations.

Mr. Thompson quickly raised more than a half million dollars atop a war chest of $236,313 from the previous cycle. Mr. Espy raised a little more than $313,000, much of it from Mississippians who usually give to Republicans. Republican money made such a key part of Mr. Espy’s fund-raising that the Mississippi Republican chairman, Jim Herring, called on state’s GOP to give to the Republican candidate in the district instead.

No Democratic member of Congress donated to Mr. Espy. Capitol Hill Democrats noted that the DCCC and Mr. Thompson successfully froze out Mr. Espy from major party donors outside the state.

In addition to the fund-raising gap, Mr. Thompson emphasized his Washington experience during the primary campaign and had former colleagues of Mr. Espy from the state legislature lament that the challenger offered only “fancy talk and untrue rhetoric.”

Mr. Thompson easily survived what had been believed to be his toughest electoral challenge yet, 65% to 35%.