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WASHINGTON — Primary season is almost over, but not before Democratic incumbents run a two-week gauntlet in the final stretch, starting with a closely watched matchup in JFK's old Massachusetts turf Tuesday.

In the only congressional district in New England where racial minorities outnumber whites, Ayanna Pressley, the first woman of color elected to Boston's City Council, is hoping to upset Rep. Mike Capuano, D-Mass., a white man who hasn't faced a serious electoral challenge since winning the seat in 1998.

Both are progressives who acknowledge they would vote almost exactly the same way. But Pressley is calling for a more representative and active leadership, while Capuano says he has the experience and clout in Washington to deliver for constituents back home.

Limited polling has shown Capuano with a healthy lead, but turnout is difficult to predict in the day-after-Labor Day primary, so analysts say Pressley has a path to victory if she can turn out a large number of young people and minorities.

Next up, on Thursday in Delaware, Sen. Tom Carper, D-Del., faces a challenge on his left flank from Kerri Evelyn Harris, a 38-year-old African-American Air Force veteran who is gay.

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Harris is a heavy underdog, having reported spending only $69,000 as of mid-August, compared to Carper's nearly $1.6 million.

But she is being boosted by national progressive groups aligned with Sen. Bernie Sanders, I-Vt., who say Carper is the most conservative blue-state Democrat in the Senate and hope the challenge will, at a minimum, push him to the left.

Carper is the only Democrat still in the Senate (and one of only three total) who voted to confirm Brett Kavanagh to the D.C. Court of Appeals in 2006. Kavanagh is now President Donald Trump's second Supreme Court nominee; his confirmation hearings started Tuesday.

Harris has also taken issue with Carper’s more moderate stances on everything from criminal justice reform to banking regulation in a state home to a large financial sector.

"The weekend before my election victory, Kerri came up to New York to help," Alexandria Ocasio-Cortez, who ousted a Democratic incumbent in her own primary, said at a rally in Wilmington last week. "She got my back, and now I'm here to get her back."

Next Tuesday, voters will choose a nominee in a crowded Democratic primary to fill an open seat in a competitive New Hampshire House district. One of the candidates is Sanders' son, though he is not seen as having a strong chance of success.

A day after that, progressives in Rhode Island are hoping to shake up the reigning conservative Democratic establishment, which has faced rare national scrutiny this year after supporting a Trump-voting Republican over a liberal woman incumbent.

The state is entirely run by Democrats, but of a breed seen hardly anywhere else in the country. Last week, Right to Life, the state's leading anti-abortion group, endorsed all six of the state legislature's Democratic leaders, while several enjoy strong ratings from the NRA.

But Planned Parenthood and other liberals groups are expecting to make gains this year, and the governor, lieutenant governor, and others all face primaries.

Finally, on Thursday September 13, the primary season finishes with perhaps the biggest, most ill-tempered, and highest-profile Democratic contest of the year — the faceoff between New York Gov. Andrew Cuomo and "Sex and the City" actress Cynthia Nixon, who is challenging the governor from the left.

Nixon is trailing badly in the polls, but seems determined to go down swinging, and Cuomo has eagerly hit back.