[kbutler]

Looks like capitalization as a general emphasis - if you just scan capitalized words:

Americans Bonus Pay Increase Passed Tax Cut Jobs Bill

Makes a good summary of the points they want to emphasize, that Americans get a bonus because the government is progressing on the Republican+blue-collar agenda.

[spacehome]

(For when tweets are TL;DR)

[k_]

Having tl;dr tweets shows how far twitter has gone from the original concept.