Doctrinaire liberals tended to underestimate Alan Colmes, who co-hosted Fox News Channel’s Hannity & Colmes for a dozen years and was frequently derided as Sean Hannity’s foil. He was, they claimed, a weak debater, insufficiently aggressive in fighting right-wing nonsense.

Former Saturday Night Live performer and Air America radio jock Al Franken, now a Democratic U.S. senator from Minnesota, couldn’t resist mocking Colmes as “a moderate milquetoast” and “liberal on-air punching bag” in Lies and the Lying Liars Who Tell Them, his best-selling takedown of Fox News and other conservative-leaning outlets.

Colmes, who died of cancer Thursday morning at the untimely age of 66, was even a juicy target for Triumph the Insult Comic Dog, comedian Robert Smigel’s alter-ago, who verbally assaulted Hannity’s so-called “sidekick” at the 2004 Democratic Convention.

“He’s Hannity’s bitch. Let him in!” the cigar-chomping sock-puppet shouted as Colmes waited amid a crush of locked-out delegates to be allowed into Boston’s Fleet Center. When convention officials finally relented and Colmes slipped through, Triumph yelped: “Thank God they just let the doormat through the door! Get in there and get your butt kicked by Sean Hannity!”

Ellis Henican, who has often substituted as host on Colmes’s nightly Fox Radio Network show, especially as the latter succumbed to illness in recent weeks, said such critiques—and they were numerous—reflected a misunderstanding of Colmes’s role in the political cosmos, especially from mid-1996 to January 2009, when Colmes co-starred as the progressive voice on the eponymous prime-time cable program.

“Being a liberal commentator on Fox is like being the visiting team; the audience, by and large, doesn’t agree with you, your co-host doesn’t agree with you, most of the guests don’t agree with you, so you live with the daily challenge of needing to perform in front of an audience that is not inclined to like you,” Henican told The Daily Beast. “You can’t just shout. I would tell the people who felt he was not sufficiently bombastic to go see how well they would do if their technique in front of an audience like that is just to be a bigger asshole than the other guy.”

Henican said Colmes was aided immeasurably by his pre-Fox News training as a standup comic—a line of work in which he was able to make a good living in the ‘70s and early ‘80s before he went into radio, and then television, full-time.

“You have to use other techniques—you have to use humor, you have to use charm,” Henican said. “You have to learn to twist a question in some unexpected way. If you don’t, you’re gonna get run over like a freight train. That was both Alan’s talent and his challenge.”

Author, essayist, and occasional Daily Beast contributor Tracy Quan, who used her previous career as a high-priced call girl as fodder for a series of novels, said she thought of Colmes as her “mentor,” a good friend who was always generous with advice about television and radio appearances, or as a sounding board about her personal life, over lunches, teas, or when she was a guest on his various radio gigs over the years. (She never saw the rail-thin Colmes take an alcoholic drink.)

“His heart was in it—he really believed in certain things, he wasn’t just a hack,” Quan said. “I don’t think that is necessarily true of some people who do political commentary.”

Henican, for his part, explained: “He lived in a world where, politically, he was in a very distinct minority, and the challenge was not about having the perfectly crafted argument or shouting louder. The challenge was, ‘Can I reach these people who don’t want to hear from me and maybe make them listen for a minute.’”

As a measure of Colmes’s success at that goal—and his apparently universal reputation as a decent guy who was unfailingly generous to coworker and competitors—his Fox News colleagues reacted to Thursday’s awful news with an outpouring of raw grief.

“I have a hole in my heart today,” said a clearly devastated Hannity, who phoned in to America’s Newsroom, the Fox News morning show. “Everybody loved Alan. Everybody liked him…The world is a little darker place today because a really great human being left us.”

Hannity added: “He was just a guy with a great sense of humor, a guy who had a human level of decency and love and kindness…He was one of the funniest guys I ever met…He had a passion for the microphone.”

Hannity, whose office at Fox News’s Manhattan headquarters is next door to the one Colmes used, recounted that shortly after he received his shattering diagnosis, Colmes dropped by to tell him.

“We had a long, really deep, personal chat. We talked about our deep friendship—how blessed we were to be good friends…He said, ‘What I’m most worried about is Jocelyn’—his wife. ‘I know she’s gonna take this harder than me.’ He was facing a very difficult uphill battle…He wasn’t thinking about himself, he was thinking about his wife, his family…I just want people to know that this was a good man with a great big heart.”

It turns out that Colmes’s wife, Jocelyn, is the sister of his once-frequent debating adversary, conservative talking head Monica Crowley, who faced off against her brother-in-law nearly every Friday on The O’Reilly Factor and was preparing to join Donald Trump’s White House staff until she was waylaid in early January by a plagiarism flap.

“I am heartbroken at the loss of my sweet brother-in-law Alan Colmes,” Crowley wrote on her Facebook page. “Alan was a true gentleman in every sense of the word. He took his beliefs and work seriously and at the same time lived his life full of joy, laughter and commitment. He loved what he did for a living, and he loved those around him—without condition.

“During the most heated political debates, his infectious sense of humor would come through, and before you knew it, even his staunchest political opponents were smiling.”

Tributes, meanwhile, abounded on social media. Megyn Kelly wrote on Twitter: “Heartbroken my friend Alan Colmes has died. He lit up the FNC halls w/his kindness & humor. Incredibly positive force. Prayers 4 his family.”

Glenn Beck tweeted: “RIP . Shock. While is [sic] disagreed with him on many things he was a good and decent man. Indeed, all that matters in the end.”

Brit Hume tweeted: “So sad to hear of the death of Fox News colleague Alan Colmes. He and I agreed on little, but I liked him immensely. Good guy. R.I.P.”

Ann Coulter tweeted: “WHAT? passed away????? Noooooooooooo! Very sad. He was a good guy. Always surprised people that way.”

Colmes, a native New Yorker, grew up in a Jewish family, the grandson of Ukrainian immigrants, and gravitated to the campus radio station at Long Island’s Hofstra University.

After becoming a standup and achieving moderate success in the comedy clubs, he exchanged that career for talk radio, toiling at a variety of stations, big and small, until then-Fox News chief executive Roger Ailes hired him for Hannity & Colmes in 1996 for the launch of the cable channel.

Although Colmes repeatedly insisted that leaving the popular prime-time debate show was his choice, many believe it was Ailes who decided to remove him as Fox News, in 2009 the top-rated cable outlet, positioned itself as the most vociferous media critic of the incoming president, Barack Obama.

Colmes never complained, never explained.

“Roger ran Fox,” his friend Henican said. “Alan had been in this business long enough to know that we all should be grateful for the opportunities that we get, and the way to win is to keep going and do well with whatever the opportunities are. I didn’t detect any bitterness in him about it.”

Henican is scheduled to host a tribute show 6 to 9 p.m. ET tonight, Thursday, on the Fox Radio Network.