I always assumed that libs simply hated anyone that disagreed with them. It's certainly what turned me away from the progressive movement.
That's your mistake.
Now, imagine by analogy there's a news event - 'bring back segregation event held'. You are with a group of progressives, and they say 'man, how horrible those people stand for that, what bigots'.
It might come across to you like 'they don't like people who disagree with them'.
But that's not it. It's that they don't like the harm, the injustice, to a group like the blacks who are the target - and have long been - of that bigotry. It's emotion of passion for the rights of the blacks. It can come out as anger at, disdain for, the bigots - very negative to them for their 'backwardness' - but even about them, progressives are 'on their side'; they don't want to hurt them, other than to get them to stop hurting others, and to 'develop' to realize the error of their ways.
Progressives are largely about that - against injustice and people who 'don't care about injustice'. They're for opportunity for everyone. They're for rational policies for the 'good of the people'.
They are not for 'big government' - compare JFK/LBJ/Clinton's government size to Reagan and on Republicans, despite their having a more progreessive agenda - they support some government that's 'good for the people', and are willing to pay for it raising their own taxes along with others'. Things progressives are especially in favor of spending on are good for the country - education, anti-poverty, jobs, resources to protect the public from the people who cheat, who are 'special interests' against the public interest, public or private.
It seems to me progressives are the ones who actually support democracy - the public votes to get something done, the public pays for it to get done, and it's done. Not just 'we hate elected government!'
That's not to be confused with supporting the corruption of government - when the people are led, with various means, to elect leaders who don't serve the public interest, and hurt it.
Progressives do balance that individual freedoms are unquestionable - and how the good of others needs some limits on him. One guy upstream can't pollute the river for everyone downstream. One industry like banks can't just pursue their own interests to where they're 'too big to fail' and they can economically blackmail the public to get financially exploited. Monopoly isn't ok. One industry can't increase its profits by polluting the environment where the costs are pushed on the public.
You can disagree with their positions on an issue and if your motives are good, not 'let you screw others'. you will get listened to by some. As in every major political movement, some are more ideological.
They don't trust things like big money from those who stand to make a lot of money by defeating the public interest to pay for propraganda think thanks and marketing campaigns to mislead voters and buy elections.
You should have higher standards for being on the right side of the issues, not just say 'forget them' for such a weak reason.
I base my association on the positions. The old 'I'd like to have a beer with him even if his policies are terrible' doesn't work (not that I'd like to have a beer with Bush, but many would, or would have).
You want to oppose the group with the right positions because you imagine they're not very tolerant of other views? Does that make any sense when it leads to bad policies?
As for openness to disagreement, enjoy the next tea party with your "We need more government stimulus" sign. I'm sure you will get a welcoming group.