First, what leverage did the progressive caucus really have?

Second, you misrepresent at least some of the Republican votes. For example, "Don Young of Alaska, 88, is the Republican Party’s longest-serving member, having represented Alaska for 25 terms. He endorsed the bill in September, arguing the party has always supported funding roads and bridges and emphasizing that past infrastructure votes were “darn near” unanimous."

Regarding, we have always contracted private companies to do road and bridge construction. There is nothing new there. There may be other "privatization and wealth transfers" in the bill, though you don't cite them, but the "road & bridges" element is standard business for decades.