WASHINGTON – Chris Van Hollen has spent decades quietly helping shape U.S. foreign policy in Congress, earning a reputation as a serious lawmaker from the establishment wing of the Democratic Party.

But it wasn’t until his trip to El Salvador last week that the Maryland senator seized the national spotlight, rallying in defense of a constituent who was wrongly deported by President Donald Trump’s administration without due process. Though he ultimately didn’t secure his release, Van Hollen’s effective diplomatic pressure yielded a meeting with Kilmar Abrego Garcia, a 29-year-old man with legal status who has been imprisoned by El Salvador’s government despite not being charged with any crimes, and put the White House on its heels about the legal and humanitarian consequences of its severe immigration policies.

“If we allow the Trump administration to disregard court orders and tear up the rights to due process, then the freedom of every American is in jeopardy,” Van Hollen told HuffPost in an interview last week. He slammed Trump for defying decisions by multiple federal courts, including a 9-0 ruling from the Supreme Court telling the administration to facilitate Abrego Garcia’s return to the U.S.

The 66-year-old lawmaker’s stand offered a lesson in how to break through the fractious media environment with a compelling argument opposing the Trump administration, especially at a time when many in his party are struggling to do the same. Democrats were caught flatfooted in the first months of Trump’s presidency, reeling over the aggressive pace of his efforts to dismantle the federal government and lay off thousands of federal employees. They badly managed last month’s government funding fight, getting outplayed by congressional Republicans and angering Democratic voters.

But now, the Trump opposition is finding its footing with standout moments from prominent voices on the left, including Sen. Cory Booker’s (D-N.J.) record-breaking uninterrupted 25-hour speech on the Senate floor in defense of democratic institutions and the rule of law, and a national “Fighting Oligarchy” tour by Sen. Bernie Sanders (I-Vt.) and Rep. Alexandria Ocasio-Cortez (D-N.Y.) that drew crowds of tens of thousands of people.

Dozens of Democratic lawmakers have traveled to GOP-held districts across the country to put pressure on Republican incumbents unwilling to hold town halls and engage with angry constituents. And a group of House Democrats followed Van Hollen’s lead this week, traveling to El Salvador to push for the release of other migrants deported from the U.S. who are imprisoned there.

“The current divide in the Democratic Party is not between left versus moderate, it’s between those who have fight and backbone and those who are passive and not taking the risks. And it seems like a prerequisite for being applauded in this moment is the willingness to take risks,” Adam Green, co-founder of the Progressive Change Campaign Committee, told HuffPost.

“Hopping on a flight to El Salvador, putting his own safety at risk and probably getting at least half of the national media exposure he’s had his entire Senate career … seems like a risk that had payoff for the broader cause and for himself, and we need more of that,” Green added of Van Hollen.

At first glance, Van Hollen makes for an unlikely resistance hero. He’s not a fire-breather, he typically doesn’t garner headlines and prefers working behind the scenes. He’s had a very traditional trajectory into the Senate: He was elected to the House in 2003 and worked his way up to a leadership role before his 2016 Senate run to replace the retiring Sen. Barbara Mikulski (D-Md.). He defeated former Maryland Rep. Donna Edwards in a hard-fought primary where he was viewed as the establishment Democratic candidate in the race.

But recently, things have been changing. In the U.S. Senate, Van Hollen emerged as a leading critic of Israel’s conduct during the war in Gaza. Last year, he criticized President Joe Biden for what he saw as his “shameful” inaction in holding Israel accountable for barring aid into Gaza amid a hunger crisis, saying it would forever haunt his legacy. And he rallied Democrats in pressuring Biden’s administration to toughen oversight of U.S. arms shipments abroad, requiring that weapons be used in accordance with international law.

“There’s no point in being in the United States Senate if you cannot look yourself in the mirror at the end of the day,” Van Hollen told HuffPost last year amid his Gaza war activism.

The trip to El Salvador was politically chancy. While it had the opportunity to draw much-needed attention to the case, it also carried the possibility of being a political embarrassment if Van Hollen couldn’t get access to Abrego Garcia and had to return home empty-handed.

At first it seemed very much like that might be what would happen: El Salvador’s vice president stonewalled his requests upon arriving in the country, and his trip drew attacks from the White House and El Salvador’s government. Trump said the senator “looked like a fool” by “standing in El Salvador begging for attention from the Fake News Media,” calling him a “GRANDSTANDER!!!”

They also accused him of sympathizing with a gang member: Trump officials have claimed that Abrego Garcia is a member of a gang to justify his arrest and deportation, an accusation Abrego Garcia and his lawyers have denied.

The Maryland man had not been seen or heard from since March 15, the date he and hundreds of other migrants were sent to the CECOT mega-prison in El Salvador. Van Hollen’s Thursday photo of himself sitting and speaking with Abrego Garcia at a hotel in El Salvador was the first time he had been seen publicly. The photograph prompted a reply from Salvadoran President Nayib Bukele, who mocked concerns about Abrego Garcia’s well-being, pointing to a pair of garnished drinks on their table. But Van Hollen said that Salvadoran officials staged the photo, planting the drinks in front of him unprompted, to make it appear as if Abrego Garcia is living the good life despite being held in prison.

“All of that was a setup,” Van Hollen said to reporters upon returning to the U.S.

Democrats praised Van Hollen for sticking to his principles this week.

“Chris Van Hollen is smart, dedicated and fearless,” Senate Minority Leader Chuck Schumer (D-N.Y.) said in a statement to HuffPost. “It was tough enough going to El Salvador and confronting Bukele’s government, but securing a meeting with Abrego Garcia and not letting Bukele hijack the meeting was an incredible feat.”

“For as long as I’ve known my friend Senator Chris Van Hollen, he’s been committed to standing up for Marylanders and for right over wrong,” added Rep. Steny Hoyer (D-Md.). “That commitment — and Chris’ moral clarity — brought him to El Salvador last week. We will need more of that type of principled leadership in the months and years to come.”

Van Hollen’s hands-on approach to challenging Trump’s administration has differed from other high-ranking Democratic officials. California Gov. Gavin Newsom and Michigan Gov. Gretchen Whitmer, two potential 2028 presidential contenders, for example, have at times downplayed their Trump criticism. Other Democratic governors like Josh Shapiro of Pennsylvania and Wes Moore of Maryland, meanwhile, have preferred to keep a lower profile.

After Newsom seemed to refer to Abrego Garcia’s unlawful deportation as “the distraction of the day,” Van Hollen pushed back in a Sunday interview with NBC’s “Meet the Press.”

“I think Americans are tired of elected officials or politicians who are all finger to the wind,” Van Hollen said. “Anybody who can’t stand up for the Constitution and the right of due process doesn’t deserve to lead.”

The senator has pledged to keep working on getting Abrego Garcia home, noting that even some Republicans are starting to come around to concerns with the Trump administration’s deportation policies.

“I think more and more, certainly libertarians and other conservatives who are actually looking at the facts of this case are very worried about the idea that the government of the United States can deprive someone of their liberty, abduct them, send them to El Salvador without knowing where they’re going, lock them in prison ― to do all that without any due process. That is a scary proposition,” Van Hollen said Monday in an interview on MSNBC’s “Morning Joe.”

“And if you don’t fight for the constitutional rights of one person, as I say, others can be next,” he added.

Arthur Delaney and Akbar Ahmed contributed reporting.