Most places on the internet say the U.S. Constitution is 4440 words long. However, I set out to find how many characters are in the United States Constitution.
A text copy of the U.S. Constitution can be found at tcnbp.tripod.com and they claim "that this text is the most accurate rendition of the Constitution to be found outside the National Archives". Sounds good enough for me.
I downloaded the text and removed any instance of 3+ paragraph breaks and made every paragraph have 2 breaks. Not that it matters when counting characters, but I just wanted a nice and simple copy of the Constitution.
tchnbp's character count differs from the 4,440 from other places. NanoCount found 5,064 words. That's a little disheartening, but I continued on. There are 32,026 characters in the U.S. Constitution according to the copy available from tchnbp. It would take 229 Twitter posts to spell out the U.S. Constitution. That's if you're willing to break up words.
Now, the word count for the U.S. Constitution with the Amendments comes to 8,160. The character count with Amendments is 50,534. It would take 361 Twitter posts to spell out the U.S. Constitution with Amendments (agains assuming that you're willing to break up words). So you can make one tweet a day and be able to cover the entire U.S. Constitution with Amendments in less than a year!