I have a MacBook Air (Mid 2012) and was thinking about buying 2 Dell UltraSharp u2414h monitors. Would it support daisy chaining these two monitors with the mini DisplayPort to DisplayPort cable connected from the MacBook to the monitor, and the other mini DisplayPort to DisplayPort cable connected from the monitor to the second monitor?
DisplayPort protocol doesn't chain. It is a one to one technology, so you need two ports on the Mac.
Thunderbolt does chain, so you could have one Thunderbolt Display and then plug a second monitor (either Thunderbolt or Mini DisplayPort) into the first monitor's second connector.
That works very well.
No, it wont. You must have at least a Thunderbolt 2 connector. Unfortunately Yosemite doesnt support daisy chaining.