As the White House gears up its election-year pitch taking credit for lowering prescription drug prices, it faces a key unknown: Will voters notice any difference?Why it matters: One of President Trump's primary answers to concerns about affordability may fall on deaf ears if patients don't see results — and policy experts have warned many won't.Driving the news: Trump will almost certainly point to his pricing deals with leading drugmakers during Tuesday's State of the Union, along with the lau...