As a casual observer, it certainly does seem like the political right in America has consistently been more willing and eager to bend the rules of the information game - up to and including willfully propagating falsehoods. This has at a minimum been repeatedly evidenced over the last 20 years, first in cable news and now online.
Is the solution - as the OP implies - for the left / center left to adopt the same dirty tactics as their counterparts? Is there any alternative? I'm sure every rational individual (a group in which I hope to include myself), would really just prefer if everyone started behaving like adults and returned to discussing issues in what at least looks like good faith. Is that at this point a pipe dream?