President Trump has dozens of declared presidential candidates ready to take him on in 2020. Aspiring chief executives across the United States are deriving plans to attract primary voters. Some are using the issue of cannabis legalization to help voters sort through all the candidates. Once a liberals-only issue, times are changing: Now, Democrats, Republicans, and libertarians are having their say on it.  For example, Trump’s sole declared primary challenger, at least until now, former Governor of Massachusetts William Weld, is a libertarian who is very outspoken about his advocating legalization. By contrast, current Democratic frontrunner, former Vice President Joe Biden, cannot understand why folks even want to legalize, having established himself as a fierce opponent back in the 1990s already.  So who thinks what of weed? We did the research, and this is what the five top candidates have to say: 1. Joe Biden Joe Biden, the former Vice …