No.
The overall goal of the Left is to "equalize" society. To that end Liberals want to transfer money, resources, and privileges from you (i.e. the wealthy, productive, efficient, educated, rational population) over to them (i.e. the poor, downtrodden, uneducated, inefficient, and unproductive population).
The Left uses several tools toward this end.
1. The press. What the media reports and what gets high praise (re: entertainment) tends to either support the overall goal directly or at least undermine a facet of an opposing ideology.
2. Government. The Left proposes the same solution to every problem, no matter the cause or effect: government. Are people unemployed, then the government needs to provide unemployment benefits or make work via social spending. Are people discriminated againt, then the government needs to insert itself into every case and force people to no longer discriminate. Name a problem and the Left has a government solution for it.
3. Education. The tenure system has long been co-opted by the radical Left. Our children will be inundated by liberal mush long after Left-wing ideologies fade from fashion simply because we can't fire all of the pedarasts for keeping their catamites locked in their ivory towers.
4. Dependency. Many people are compelled to vote with their pocketbook. The Left has long taken advantage of that fact and used their positions of power to create generations of people who are entirely dependent upon them.
So why can't the Left be reasonable or responsible?
Because it isn't reasonable to take from one productive group to give to an unproductive group (save for a few worst case, safety-net exceptions). Nor is it responsible to create generation after generation of dependents. 40 years and three generations after Jim Crowe laws have been repealed, why are Affirmative Action programs still needed to ensure that some groups find jobs and college admissions? The only answer is that earlier Affirmative Action programs created more dependency, not less.
Furthermore, the Left will adopt any position that fosters its agenda, even if said position conflicts with existing positions. To wit: labor unions versus environmentalists. Unions want jobs (ala drilling in ANWR). On the other hand, environmentalists want an end to development (which they refer to as exploitation of Mother Earth). The enviro-nazis also find themselves in conflict with urban Lefties. Urban Lefties want cheaper housing, but enviro-lefties fight "urban sprawl" tooth and nail. Without new housing, however, the Supply versus Demand crashes the financial hopes of many urban Lefties. There just aren't enough homes in most urban areas.
Moreover, Lefties can't be reasonable or responsible because they are Machiavellan. By that, I mean that Lefties will say any lie and engage in any subterfuge to promote their cause. To them, the Ends justify the Means.
So they tell us that abortions are rare. They tell us that guns cause crime and suicides. They tell us that it's a good idea to pack the poor into subsidized housing. They claim that it makes sense to release criminals from prison early (10 year sentences often mean 10 months now). Drugs are good, they say, but smoking is bad, et al. Rent controls will keep housing costs low, they claim. Regulation will keep electricity costs down, they say.
Can the Left ever be reasonable or responsible?
No.
The Left is our enemy.