Was watching The Sunday Politics discussion on the 'two child policy' a little while ago, and rather shockingly (but unsurprisingly) the person speaking for the Government, when pressed on the lack of evidence resorted to second-hand anecdote. This sort of thing is ubiquitous in political discussion even on television and radio, where the single most common format for hashing out issues is to set two partisans against each other and allow them to make time-limited statements in opposition to one another. Outright lies often slip by, context is frequently missed and evidence entirely ignored.
At times I long for an Institute of Evidence (-based-policy) which could independently adduce arguments made implicitly or explicitly as part of policy positions, and aggregate and assess the state of available evidence for those arguments where possible while avoiding addressing the arguments themselves, except in so far as they make statements of pre-existing fact. Such an organisation would require strict rules and regular review by external experts in the field as to its methodology.
I'd also like a requirement that every election, every referendum and every vote of every kind should have relevant details (manifesto commitments, policy positions, argument summaries) presented on a website in some basic form and clearly signposted to voters via a web address, with links to third party (political or otherwise) sites for additional information.
I'd very much like it if there was an aggressive attempt to ensure that all voters have easy access to the minimum necessary information required to make a decision on all matters on which they might have to vote. And if all politicians had to be concerned about making false or deceptive claims regarding facts which can be clearly established by reliable evidence.
I'm not convinced it would be that difficult to do.