A casual glance at the results of Tuesday's primary election might suggest an inconclusive and even contradictory theme.
Political fortune shined on the Assembly's stalwart speaker, Sheldon Silver, who demolished two youthful opponents, while, in an overlapping district, another veteran lawmaker, Senator Martin Connor, was vanquished by a 28-year-old upstart with a Yale degree, Daniel Squadron.
A common thread that has not gone unnoticed among lawmakers is that Messrs. Silver and Squadron, as well as two other Senate candidates in high-profile races, were all endorsed by the Working Families Party, an umbrella group of community organizers and labor unions that has become a potent force in Albany politics.
In the case of Mr. Squadron, a former staffer to Senator Schumer, the party's large-scale canvassing effort may have been a decisive factor. Officials say its paid workers and volunteers knocked on 40,000 doors in the Brooklyn and Lower Manhattan district, identified 9,000 likely supporters of the candidate, and helped shepherd 5,000 of them to the polls on Tuesday. Mr. Squadron won by 2,000 votes.
"They run a very, very effective field operation," a chief political strategist for the Senate Democrats, Douglas Forand, said. "In a low-turnout election, what's most critical is identifying and turning out the vote."
The party, which has its headquarters in Brooklyn, also helped the campaigns of a former heavyweight boxer, Joe Mesi, who won a Senate primary in Western New York, and Kevin Parker, a Brooklyn Democrat who fended off challenges from two City Council members.
The primary election results are the latest feather in the cap of an organization that is aiming to become the third-largest party in the state. The Working Families Party also commanded the ground operations of the two most recent Democratic victories: the special election campaigns of Craig Johnson in Long Island and Darrel Aubertine in the North Country.
The party is flexing its muscles as Senate Democrats, who trail Republicans by one seat, are in position to seize the majority in November.
For the unions and other left-leaning groups, such as the Association of Community Organizations for Reform Now, that finance the group, the show of strength and the expanding roster of lawmakers in their fold are crucial, as the Senate Democrats have yet to set their agenda should they assume power.
In recent months, disagreements within the conference have flared on issues ranging from taxes to rent regulations. Working Families Party officials say their role in the elections gives them significantly more leverage to mold policy to the party's liking.
"We don't want just a change of parties. We want a change of policies," a spokesman for the party, Daniel Levitan, said. "We want to flip the Senate and also make it better."
Around Albany, the targeting of Mr. Connor in particular carries symbolic weight. Party officials said the senator had a voting record they mostly approved of, but that they wanted a more energetic force behind their policies. The obliteration of a 30-year incumbent will likely serve as a warning sign to other vulnerable Senate Democrats.
Working Families officials are anticipating a fierce struggle over rent laws in New York City. The candidates they have supported have pledged to beat back attempts to do way with rent regulations and support handing over the authority to change the laws to the City Council, which favors tighter controls.
Their endorsements have also gone to candidates who support raising taxes on New York's wealthiest residents. The Democratic leader in the Senate, Malcolm Smith, has taken a more moderate position on both issues.
"Having the Working Families Party in the position to weigh in with members of our conference they helped get elected in favor of a progressive reform agenda will be tremendously helpful," a Democratic senator of Manhattan, Eric Schneiderman, said.
Behind the party are some of the biggest unions in the state, including the United Federation of Teachers and 1199 SEIU, the health care employees union. For the unions, the party offers them a place on the ballot, a sophisticated piece of political machinery to enforce their platform, and another point of access to lawmakers, who are often responsible for paying for much of the field operations.
The party also allows them to lobby the Legislature on issues in a less direct manner. The UFT, for instance, has been a key contributor to the party's effort to persuade the Legislature to raise taxes on the state's millionaire residents.