Abbott had go find a legal and hopefully court-proof way of acting re his state powers as the governor. He can do a lot on private lands.
All he needed at any given time is the TX and US Constitutions. People tend to forget that the States created fedgov and granted a few powers to fedgov and that the States are supposed to be sovereign. State is another word for country. A sovereign entity.
That the general, great and essential principles of liberty and free government may be recognized and established, we declare:
Sec. 1. FREEDOM AND SOVEREIGNTY OF STATE. Texas is a free and independent State, subject only to the Constitution of the United States, and the maintenance of our free institutions and the perpetuity of the Union depend upon the preservation of the right of local self-government, unimpaired to all the States.
https://statutes.capitol.texas.gov/Docs/CN/htm/CN.1.htm
The United States shall guarantee to every State in this Union a republican form of government, and shall protect each of them against invasion; and on application of the legislature, or of the executive (when the legislature cannot be convened) against domestic violence.
US Constitution
Every red state should be suing fedgov over this and in the meantime, taking matters into their own hands.
Furthermore, since most of those migrants stayed under the bridge, it doesn’t really matter whether or not he waited a few days or not: they weren’t going anywhere.
At least Governor Abbott is ACTING, even in the face of the federal government’s threats and considerable resources.