House Minority Leader Nancy Pelosi (D-Calif.) is joined  by Rep. Steve Israel (D-N.Y.) at a news conference to announce her Democratic leadership team Nov. 17, 2014. Israel, a top adviser to Pelosi, announced Tuesday that he would not seek reelection next fall. (J. Scott Applewhite/AP)

Rep. Steve Israel (D-N.Y.), a onetime rising star with ambition for the Senate or even House speaker, announced Tuesday that he would not seek reelection next fall after 16 years on Capitol Hill.

Israel’s announcement, a surprise given his recent appointment as a top adviser to House Minority Leader Nancy Pelosi (D-Calif.), came on the first day of the new session of Congress. His decision to retire follows the move by Rep. Chris Van Hollen (D-Md.), another Pelosi confidant, to give up his House seat to run in a contested April primary for the seat of retiring Sen. Barbara Mikulski (D-Md.).

Israel, 57, whose homes are adorned with pictures of him with Bill and Hillary Clinton, also will leave office at the moment when he hopes to see former secretary Clinton sworn in next January as the first female president. But after considering this “decision deeply,” Israel said he wants to focus  on his burgeoning writing career after successful reviews of his first book, “The Global War on Morris,” a political satire.

“I hope to continue to be involved in public service, but it is time for me to pursue new passions and develop new interests, mainly spend more time writing my second novel,” Israel said in a statement. His decision was first reported by Long Island’s Newsday.

His Long Island-based district skews toward Democrats, but is not a slam dunk. In 2014, he won with less than 55 percent, Israel’s lowest tally since his first election in 2000.

In early 2009, after President Obama appointed Clinton as secretary of state, Israel had hoped to succeed her in the Senate. He briefly considered waging a primary against Sen. Kirsten Gillibrand (D-N.Y.) after she won the interim appointment, needing to win the seat outright in 2o10.

Instead, Israel was talked into devoting his efforts to the House, and in 2011, he took over the Democratic Congressional Campaign Committee, the campaign arm for Democratic leadership. Following four years of Van Hollen’s tenure at the DCCC, Israel chaired the committee for four years, working closely with Pelosi’s political operation.

The initial success of 2012 — picking up eight seats and cutting the Republican majority to within striking distance — was followed by a GOP-prompted shutdown of the federal government in October 2013, leading to hopes that Democrats would defy history and win big in the second midterm election of a president. Instead, the roll-out of Obama’s Affordable Care Act floundered amid a series of other self-inflicted wounds for Democrats.

The party’s message was muddled, at best, and 2014 turned brutal: Democrats lost an additional 13 House seats and nine Senate seats, and were embroiled in bitter infighting this time a year ago.

Some House Democrats questioned whether Israel’s DCCC properly saw the wave coming against them, believing some seats were lost because of political malpractice. Pelosi stuck by Israel, awarding him a newly appointed position at her leadership table: chairman of the Democratic Policy and Communications Committee, a shop that was supposed to craft a new message focused on the middle class.

[Read how Pelosi plotted a path forward after 2014 defeats]

He tried to argue that too many people were left behind by an uneven economic recovery that was delivering great results for some. “It’s my economy, stupid,” Israel told The Washington Post 13 months ago, giving a twist to the “It’s the economy, stupid” mantra from 1992 Clinton presidential adviser James Carville.

With a trio of 70-somethings atop the Democratic caucus — Pelosi is 75, House Minority Whip Steny H. Hoyer (Md.) is 76, Rep. James Clyburn (S.C.) is 75 — some viewed Israel as a potential member of the next-generation team of leaders once those veterans retired.

Now, with Israel and Van Hollen leaving the House, Pelosi has no obvious natural ally to run for one of the top two positions in leadership. No one is sure when those openings will come, and Pelosi devoted her remarks to congratulating her close lieutenant of the past five years.

“Steve is a tremendous resource in articulating Democrats’ work on behalf of hard-working families. He will be a critical resource for our Caucus in the remainder of his term and into the future.  His work for the middle class, for veterans, for the people of New York has been exceptional,” she said in her statement.