political gossip fiction, 1940s style

So in the 1940s and 50s there was a Republican Senator from California named William Knowland. His family owned the Oakland Tribune. He was by most accounts - especially Robert Caro's in his LBJ biography - rather pompous and dim, and he immolated his own career, and most of the California Republican Party along with it,* in 1958 in an ill-advised attempt to position himself to run for President in 1960.

Not so publicly known was that Knowland was having a long-term affair with a journalist's wife, named Ruth Moody. Meanwhile, Knowland's wife, Helen, was having an affair with the journalist's wife's husband, Blair. (He later served briefly as an appointee senator himself.) Accounts differ as to who started what first, but the couples were apparently close friends while they were carrying on with each other behind each other's spouse's backs.

Anyway, I read somewhere that Helen Knowland found out about her husband's affair while keeping her own affair secret, and that she wrote a murder mystery novel about the situation. Interesting, I thought, and tracked it down by inter-library loan. Presuming that nobody else will bother to read Madame Baltimore (Dodd Mead, 1949), here's ( a spoilerish description )