Sen. Charles E. Schumer (D-N.Y.) is interviewed at his office on Wednesday June 03, 2015. (Photo by Matt McClain/ The Washington Post)

Sen. Charles E. Schumer won’t talk about his leadership style for 2017, when the New York Democrat is expected to succeed Minority Leader Harry Reid (N.Y.) as the Senate’s top Democrat. Schumer demurs at any mention of his presumptive new job because “Harry is the leader”.

But ask Schumer to critique the performance of Majority Leader Mitch McConnell (R-Ky.) in his first six months on the job, and there’s a pretty good glimpse of how Schumer will try to lead the Democratic caucus after the next elections.

The New Yorker’s first order of business will be forging Democratic unity and building outward to find Republican allies. “So far McConnell has not shown an ability to manage his caucus to a unified position that gets things done,” Schumer said in a wide-ranging, 30-minute interview.

For Schumer, the critical lesson of McConnell’s reign so far is the tendency of the right wing to push McConnell into debates that were destined to fail. Schumer cited the failed bid to restrict funding for President Barack Obama’s executive actions on immigration in the winter and McConnell getting outmaneuvered by Sen. Rand Paul (R-Ky.) over the debate on provisions in the Foreign Intelligence Surveillance Act, when there was a bipartisan majority ready to support revisions to the law.

In that regard, Schumer believes that, if a leader can’t find party unity, they are destined to get driven into a corner by the minority leader, who will quickly realize the majority leader’s only hope of governing will involve votes from the opposition.

To be clear, Schumer appreciates McConnell’s political skills and his negotiating capabilities when he needs to cut a deal. He has even served as Reid’s emissary to McConnell or his GOP deputies in key moments over the past four years.

“He knows he needs to get things done, but he hasn’t quite figured out how to do it,” Schumer said.

Republicans, not surprisingly, reject Schumer’s critique. They believe that the Senate is a more functional, free-wheeling place than under the last several years of Reid’s term. They say they’re living up to to the Senate’s founders’ intention. McConnell presided over the debating and voting on of more than 120 amendments, winning approval of 30 bipartisan bills — including legislation to create a congressional review of a potential Iran nuclear deal, promote energy efficiency, and a fast-track authority for trade deals.

Moreover, senior Republicans blasted Schumer’s remarks to PowerPost, published Wednesday, laying out the Democratic plan to filibuster all 12 of the annual spending bills that fund the federal government.

[Read more on “filibuster summer" from PowerPost and the Democratic blockade to come.]

Sen. John Cornyn (R-Texas), McConnell’s top lieutenant, delivered a scathing floor speech that made note of how, with Schumer’s backing, Democrats blocked much debate in 2014 to try to protect their incumbents from facing difficult amendment votes. In that election, Democrats lost nine seats and Republicans claimed the majority for the first time in eight years, a strategy that GOP leaders often lay at Schumer’s feet.

“Stifling debate and blocking votes is a pretty lousy political strategy as well,” Cornyn said. “It’s what lost them control of this chamber last November. It’s a losing strategy, it’s a bad policy, and it’s cynical politics.”

Schumer believes that November’s crushing losses came about from a public that was distracted by global events such as the Ebola outbreak in Africa and the advance of the Islamic State in Syria and Iraq. He contends that the “fair shot” agenda, focused on issues such as raising the minimum wage and protecting reproductive rights, can be a winner in 2016.

“It didn’t resonate [in 2014] because there were too many other issues,” he said. In 2016, he said, Republicans are defending many more swing seats and there’s a legitimate chance for a net gain of the four or five seats it will take to make Schumer the majority leader.

Should Schumer take over the Senate, he will face his own renegades looking to push the party in a more liberal direction. Sen. Elizabeth Warren (D-Mass.) has already made her presence felt in debates on banking and trade, emerging as the highest profile liberal voice on Capitol Hill.

Compared to Republicans, Schumer said, “I think we’re quite unified. There’s far less division.”

He pointed to the pending battle over the appropriations bills, suggesting McConnell can’t get his right flank to simply accept now what will be the likely outcome in the fall: a protracted negotiation with White House officials and Democrats on spending levels.

“They are heading down the same cul-de-sac that they did on the FISA bill, and they’re heading down it on the spending bills. If he wanted to get something done, he should be talking to the White House,” Schumer said.

In a slight to McConnell, he credited Sen. Bob Corker (R-Tenn.), chairman of the Foreign Relations Committee, as the key player on the Iran bill. The bipartisan package that permanently fixed a Medicare funding formula and an extension of a children’s insurance program came through negotiations between House Speaker John A. Boehner (R-Ohio) and House Minority Leader Nancy Pelosi (D-Calif.).

Toward the end of the interview, Schumer’s brother called to firm up plan’s for last weekend’s dinner celebrating his mother’s birthday: Peter Lugers Steakhouse in Brooklyn. His mother turned 87 Saturday, and his father turns 92 this Sunday.

Love him or hate him, Schumer — a mere 64 years old — comes from a gene pool that could allow him to lead Senate Democrats for decades to come.

“God willing,” he said, smiling.