New York Democrat Kirsten Gillibrand on Tuesday picked up the endorsement of the feminist group Planned Parenthood's political arm -- the latest indication that there is no summertime lull for the appointed senator as she prepares for her 2010 election contest, and the possibility of a serious Democratic primary challenge by Rep. Carolyn B. Maloney.

The Planned Parenthood Action Fund is the latest of several women's groups aligned with the Democratic Party that have thrown their support to Gillibrand. This backing could be especially helpful to Gillibrand in a showdown with Maloney, who has indicated she will run in next year's special election primary and has been positioning herself to Gillibrand's left.

Maloney, who is in her ninth House term representing a New York City district, is one of a number of prominent Democrats who sharply opposed the January decision by Gov. David A. Paterson to pick Gillibrand to succeed Democrat Hillary Rodham Clinton.

As part of her ongoing effort to secure Democratic support for her 2010 campaign, New York Sen. Kirsten Gillibrand announced today she has been endorsed by Democratic party chairs from 52 of the state's 62 counties.

The list of counties shows Gillibrand has garnered support from party leaders in wide swaths of the state -- all but four county chairs in Western and Northern New York are on board, as well as New York City suburbs such as Westchester and Rockland counties and Long Island's Nassau County (home, incidentally, to one of Gillibrand's fiercest critics, Democratic Rep. Carolyn McCarthy).

Gillibrand's Achilles heel continues to be New York City, ground zero for the initial opposition to Gillibrand's Senate appointment in January and home of likely primary opponent Rep. Carolyn Maloney. Gillibrand has made strides in winning over several important downstate constituencies since replacing Hillary Rodham Clinton, who was named secretary of State. But the city's five county chairs are absent from Gillibrand's endorsement list.

However, Patrick Jenkins, an aide with the Bronx County Democrats, told CQ his county chair's lack of endorsement was not a reflection on her job thus far as senator.

Rep. Carolyn McCarthy will not challenge Sen. Kirsten Gillibrand in a Democratic primary. McCarthy, a thorn in Gillibrand's side of late, had said she would take on the newly appointed senator in 2010 if no one else did.

But McCarthy has reversed course, citing personal issues.

"I'm not running," she said Thursday afternoon.

That further clears the field for Gillibrand, who has had difficulty coalescing her delegation around her bid. Some other New York lawmakers were rubbed the wrong way by her rapid ascent to the Senate, ordained by Gov. David A. Paterson when Sen. Hillary Rodham Clinton became secretary of State earlier this year.

New York Sen. Kirsten Gillibrand will ultimately will clear the field of any potential primary opponents, the Empire State's senior senator predicted Thursday.

"I think she's going to win, and I don't think she's going to end up having a primary," Sen. Charles E. Schumer, D-N.Y., said of Gillibrand, who is seeking her first full term in 2010.

Schumer said Gillibrand, appointed in January by Gov. David A. Paterson appointed replace now-Secretary of State Hillary Rodham Clinton, was "a very capable person," who was "performing well in the Senate and earning "the respect and affection of her colleagues."

Trying to shore up her support on the left, Democratic Sen. Kirsten Gillibrand today announced an endorsement from the New York State Council of Machinists and Aerospace Workers for her 2010 Senate bid.

"Senator Gillibrand is a champion for New York's working people," said union President James Conigliaro. "She is a proud supporter of the Employee free Choice Act, universal health care, and fair trade agreements that protect American jobs."

It is the Democrat's first labor endorsement and it comes 16 months before the primary election. But the nod from the 35,000-strong machinists' state branch, alone, is unlikely to scare off many of Gillibrand's prospective primary opponents. Several New York political strategists said the union has only limited pull in state politics.