The metrical pattern is deceptively simple: Single clause declarative sentence, single clause declarative sentence, primary adjective/term of derision.
Strictly speaking, this is not a metrical pattern, and the single-clause isn't universal, but the pattern is in fact the sort of thing that can be a verse: a verse is a turn of language allowing a return, and this will do just fine. The 140-character limit also puts an upper limit to the total number of syllables, which provides a looser but still useful verse-characteristic.
So let's take the first example (@realDonaldTrump):
Ted Cruz does not have the right "temperment" to be President.
Look at the way he totally panicked in firing his director of comm.
We have a thirteen-syllable declaration (eleven words), followed by a twenty-syllable declaration (thirteen words), followed by a single-syllable derision (one word), thirty-four syllables total. The second declaration clarifies and specifies the first; the derision evaluates the second declaration and confirms the first declaration.
The second example:
Have a good chance to win Texas on Tuesday.
Cruz is a nasty guy, not one Senate endorsement and, despite talk, gets nothing done.
We have an eleven-syllable declaration (nine words), followed by a twenty-one syllable declaration (fifteen words), followed by a two-syllable derision (one word), thirty-four syllables total. As with the previous example, the second declaration clarifies and specifies the first declaration. The derision continues the evaluation begun in the second declaration and confirms the first declaration.
We get a slightly different version with the third example:
Ted Cruz should be disqualified from his fraudulent win in Iowa.
Weak RNC and Republican leadership probably won't let this happen!
We have an eighteen-syllable declaration (eleven words), followed by a twenty-syllable declaration (ten words, although it's twelve words if you count R, N, and C as different words), followed by a one-syllable derision (one word), thirty-nine syllables total. The second declaration doesn't clarify or specify the first declaration; it contrasts with the first declaration. The derision, in turn, evaluates the second declaration, but since the second declaration sets up a contrast with the first, it doesn't confirm the first declaration the way the previous examples do.
In all of these cases, the second declaration is the longer declaration, syllable-wise, and this in fact seems to be the most common pattern. It is not perfectly universal, though:
The failing @WSJ Wall Street Journal should fire both its pollster and its Editorial Board.
Seldom has a paper been so wrong.
We have a twenty-one syllable declaration (fourteen words) followed by a nine-syllable declaration (seven words) and a five-syllable derision (two words), forty-one syllables total. A possible reason for this: the second declaration tends to be the one that is emphasized: it brings the thought of the tweet to a point and thus gives us precisely what the derision evaluates. We see this in another case:
I only wish my wonderful father, Fred, gave me $200 million to start my business like lightweight Rubio says.
- total fabrication!
The second declaration is must shorter, but it is the one being emphasized.
Sometimes, Marshall notes, the third line is not an evaluation but a exhortation:
Make sure you get on the Trump line and are not mislead by the Cruz people.
They are bad!
We have a seventeen-syllable imperative (sixteen words), a three-syllable declaration (three words) specifying the reason for the imperative, and a three-syllable imperative (two words) re-emphasizing the first imperative, for twenty-three total syllables. Here we are dealing with imperatives rather than declaratives.
So we seem to have something like the structure:
(1) preliminary declaration or exhortation
(2) emphasized declaration which will serve as reason for (3)
(3) derision or exhortation
Typically (2) will be the longer line, syllable-wise, but there may be exceptions when emphasis requires it. (3) is consistently the shortest line, syllable wise. Obviously in practice there will be variation, since the actual constraint on size is based on characters rather than syllables or words, but the word and syllable counts for (1) will usually be about ten to twenty, and the word and syllable count for (3) will be about one to five.
So, let's try it. Since these tweets basically work by idea-parallelism, like ancient Hebrew poetry, we'll adapt some verses from Proverbs for ours.
Do not travel in the way of the wicked;
they will not rest until they have harmed someone.
When the wicked die, their hope perishes;
all they expected from their power comes to nothing.
A heart knows only its own bitterness,
and no one else can share its joy.
Mockers avoid the wise.
They do it so they will not be corrected.
A perverse person stirs up conflict;
a gossip divides even close friends.
Those who bribe treat it as a charm --
they think it brings success at every term.
The wicked pervert the course of justice.
They accept bribes in secret.
At the harvest sluggards look but find nothing.
They can't because they did not plow in season.
Do not exploit the poor because they are poor.
The Lord will take their side and exact life for life.
Do not make friends with a hot-tempered person!
You may learn their habits and be snared.