(CNN) Jared Kushner, the conspicuously quiet-in-public son-in-law and senior adviser to President Donald Trump, stepped up on Monday to become the face of the administration's decision to move the US Embassy in Israel from Tel Aviv to the country's contested capital, Jerusalem.

As he spoke and in the hours before and after the ribbon-cutting ceremony, Israeli troops on the border with Gaza killed at least 55 civilian protesters in what Riyad Mansour, the Palestinian representative to the United Nations, described as a "massacre."

In his remarks, Kushner blamed the deadly violence on demonstrators the White House would later claim had been provoked by Hamas, calling them "part of the problem, and not part of the solution," before pivoting to more familiar rhetoric, saying the US "recognizes the sensitivity surrounding Jerusalem, a city that means so much to so many."

He should know. In the early days of the Trump presidency, Kushner was tasked with revamping the stalled Middle East peace process. It was one piece of his broad, seemingly scattershot portfolio, which also included reforming care for veterans ( now a potentially dangerous mess ), advancing criminal justice legislation on Capitol Hill ( now near an impasse ), keeping up diplomacy with Mexican leaders ( not working out too well either ), and working up a strategy to confront the opioid crisis ( how's that going? ) -- among other things.

After nearly 16 months on the job, or jobs, Kushner has delivered little and mostly drifted into the background of Trump's chaotic operation. By using the embassy move, in which the US took Israel's side on such a contentious issue, as an avenue back into the spotlight, Kushner only further entrenched the perception that -- like his father-in-law -- he prioritizes Israeli interests, even if means further marginalizing those of the Palestinian population.

"I believe peace is within reach if we dare to believe that the future can be different from the past, that we are not condemned to relive history and that the way things were is not how they must forever be," Kushner said on Monday, with Israeli Prime Minister Benjamin Netanyahu looking on approvingly. "It will not be an easy road, and it will be filled with difficult moments and tough decisions. But, if we dream big, if we lead with courage, we can change the trajectory for millions from hopeless to boundless."

It was a nice sentiment, sure, but wholly divorced from the bloody reality of the day.

The juxtaposition of Israeli and American officials -- including Senate Minority Leader Chuck Schumer, a New York Democrat who issued an endorsement from back home -- cheering the administration's decision, as the body count grew in Gaza, will help Trump deliver on a campaign promise, but it also further reduces whatever remains of the idea that the US can act as a peacemaker in the region.

Trump had entered office promising a breakthrough. Before his inauguration in 2017, he said, "If (Kushner) can't produce peace in the Middle East, nobody can." Perhaps that's true -- maybe nobody can. But for now, it remains Kushner's brief.

As does guiding the Department of Veterans Affairs' efforts at modernizing by digitizing health records through a project, launched by the Obama administration, that would, in its current form, have military hospitals and the VA working with the same software. That hope was dimmed last week when a Pentagon report, obtained by Politico, described the ongoing process as a dangerous mess that could endanger patients' lives.

The White House defended Kushner's role -- while in the process diminishing it -- by telling Politico that the President's senior adviser wasn't involved in the decision to contract the software provider, Cerner Corp. He had simply encouraged, a spokesman said, the VA to follow the Defense Department's lead -- the idea being to keep everyone on the same page.

Meanwhile, Kushner's efforts to hammer out a bipartisan criminal justice package are facing headwinds in Congress, with conservatives pushing a plan that addresses prisons but leaves controversial sentencing standards in place. Democrats in both chambers and some Republicans, like Senate Judiciary Chairman Chuck Grassley -- who has been working on the issue for some time -- want a more comprehensive deal.

The House Judiciary Committee voted to advance the prison-only bill, called the First Step Act , last week. But its prospects for wider approval are less than bright. And with the midterm election campaign season heating up, opportunities for debate and a vote are drying up.

Kushner, despite lobbying Republican leaders to take up the narrower legislation, is unlikely to play any decisive role in what comes next, as congressional leaders make their own calculations and the balance of control on Capitol Hill comes under threat of change in 2019.

That Kushner would be unable to move Congress, where dysfunction has made a home since well before this first family arrived in Washington, is hardly a surprise. Many more experienced and savvy interlopers have seen their ambitions brushed aside by the plodding machinery of government. But it's the long-standing concern that he is uniquely unqualified -- and so potentially at risk of undermining his own agenda -- that will lead to renewed questions over how he got these jobs in the first place.

The simple, if unsatisfying, answer is that Trump trusts Kushner, making him one of the few remaining members of an exclusive, always thinning club. His status as presidential son-in-law makes it unlikely he will be forced to the outside of the club regardless of whether he can deliver results on the many, varied issues he's running.