Some kind reviews:

Booklist Reviews (12-15-16)
Here’s a western that will also appeal to mystery fans. In the third in the Mule Tamer series, Arvel Walsh, Dick Welles, and their partners go head-to-head with a nasty politician who intends to do whatever needs to be done to get his son out from under a murder charge. The story is set in Arizona in 1896, against a real political backdrop: the Silver Republicans, a short-lived offshoot of the Republican Party, and the newly formed Arizona Rangers, modeled onthe Texas Rangers, play key roles in the book (the main villain, David Gold, is a Silver Republican, and Arvel and Dick are leading the Rangers). Featuring a cast of engaging characters, an appropriately slimy villain, and a fast-paced story about murder and political corruption, it’s a surefire hit with genre devotees. Fans of the previous Mule Tamer books will have a great time, but the book is set up as a stand-alone, making familiarity with previous events unnecessary.  — David Pitt

"John Horst has a gift -- the ability to create vivid characters who leap off the page and inhabit your memory. He captures the flavor and times of the waning west in this superb tale of intrigue and villainy, The Case of the Silver Republicans, the fourth book in The Mule Tamer series. Set primarily in Arizona where all kinds of shenanigans ensue, we are also taken into old Mexico when Arvel Walsh and his Rangers travel there in pursuit of a hideous villain. Under the rule of the dictator Porfirio Diaz, Mexico is prime for the Revolution that is yet to come and Horst deftly incorporates his tale within this setting. The Case of the Silver Republicans is a stellar work of western fiction." ~ Cynthia Leal Massey, award-winning author of Fire Lilies, a saga of the Mexican Revolution, and Death of a Texas Ranger, A True Story of Murder and Vengeance on the Texas Frontier.