I know they're not the most popular writers among the Super fandom, but if DC did do a POTUS-Lex retelling I think I'd actually want Rucka and/or Ellis involved.
You use Waid, to make sure the story doesn't completely lose focus on the Super-vibe, and ensure that Clark and the rest of the cast are treated proper.
But then you use Rucka and Ellis for the dirtier, more political subplots. If you're gonna re-tell Lex as President, you want writers who have proven they can write political content in the superhero sphere, and both Rucka and Ellis are more than proven assets.
These weekly books tend to have four writers so I'd include PKJ; he's not an old school creator and he has fresh ideas, his Action run has been popular and successful, and he seems like he could bridge the gap between Waid's classic preferences and the "dirty politics" stuff you'd get from the other guys.