The UK Advertising Standards Agency calls such terms 'puffery':
3.2 Obvious exaggerations (“puffery”) and claims that the average consumer who sees the marketing communication is unlikely to take literally are allowed provided they do not materially mislead.
Here's a lawyer's interpretation of that, based on the ASA's adjudications of previous cases:
But what about claims which aren’t meant to be taken literally? Which are obviously untrue or exaggerated? For example, “Our car is so phenomenal that if you look at it too long your head will fall off”. These claims are known as “puffery”, and (thankfully) you don’t need to prove that these claims are literally true. ...
So when complainants challenged T-Mobile’s offer of “unlimited free texts forever” for customers who topped-up each month, the ASA considered that “consumers were likely to interpret the claim as containing an element of advertising puffery and were unlikely to infer that texts would be available literally forever.” Likewise, Procter & Gamble successfully defended a cat’s “comments” in their TV ad for Iams dry cat food (“Don’t get me wrong I like water; I just prefer to drink mine”) as either puffery, or just the individual cat’s feline opinion...
Advertising & Marketing Newsnotes: Distinguishing between mere puffery and misleading claims, Geraint Lloyd-Taylor for Lewis Silkin, 25 Jan 2013
Exaggerated or false praise
There has always been a fine line between legitimate puffery and misleading advertising.
Savvy readers soon learn to discount this overt puffery.
Overall, though, despite the blizzard of facts and figures, both candidates generally limited themselves to modest exaggerations and standard issue political puffery.