After acrimonious split, Bolsonaro could get back in bed with old political party

When no major parties agreed to take him on as a presidential candidate in 2018, Jair Bolsonaro found a home in the tiny Social Liberal Party (PSL). To the disbelief of the political establishment, Mr. Bolsonaro won the presidency by a wide margin — and became 2018’s biggest kingmaker, paving the way for several of his little-known party colleagues to win their races for governor and Congress. The PSL went from being a small group with eight seats to the second-largest bench in the lower house.

His stellar electoral performance gave Mr. Bolsonaro the impression that the PSL needed him much more than the other way around. After unsuccessfully trying to sequester control over the party, the president unceremoniously abandoned the group, in a bitter separation that included mutual accusations of malfeasance between him and party founder and chairman Luciano Bivar. 

Upon leaving, Mr. Bolsonaro announced that he would found his own political family, the Alliance for Brazil party. Despite the...