[header] How to win an argument when you know you are wrong [title] Reject the validity of their sources. [step] If your opponent comes at with you with evidence or statistics, do your best job to discredit their source. Talk about how their study wasn't big enough or how the reporting wasn't fact-checked or lacked integrity. 
Try to take the evidence that supports their claim and discredit it, so they can no longer use it in the argument. [substeps] You can also say that the organization or institution that ran the study has a cultural or political bias.