I've been meaning to write about this for some time but I read Barry Webb's fantastic commentary on the book of Judges last year and many things have stuck with me from reading the book.
Few things have stuck with me more than Webb's summary of the trajectory of the judges as those who governed in Israel. They move further and further away from the Lord and over time increasingly resort to the use of nepotism to continue their political and military roles within Israel or just within their tribes. Webb proposes in his book (part of the NICOT series) that nepotism and cronyism became bad enough in the period of the judges it was part of the reason Israel decided to be done with it all and make the nepotism official by the installation of a royal dynasty. Sounds ... kind of plausible. :)
Anyway, Gideon is better known for the first half of his career than his second. Webb proposes that Gideon's later ministry is characterized by a lapse into permitting and financially benefiting from idolatry and, also crucial, in conflating his divine commission to protect the people of Israel with permission to conflate that mission with settling his own personal grudges against adversaries. The exegetical and textual work Webb goes through is too complex for me to try to do justice to in a blog post that has other things in mind.
What's simple to explain, though, is Webb's observation that while Gideon refused the public offer of kingship when it was made, in private Gideon named the son of his concubine Abimelech, which means "my father is king". Webb points out that what makes Gideon unique in the Judges is that the slide toward apostasy begins within the lifetime of the judge, which had not happened previously.
As a lengthy (and typically Wenatchian) aside, it's worth noting Webb points out that there was nothing that was construed as abnormal, unacceptable, or problematic in Deborah being judge. Webb also points out that while prophecy takes place throughout the narrative it never has the predictive function usually associated with the major and minor prophets. Here we can't help but recall that Frank Crusemann pointed out in his book on the development of the Torah that in Deuteronomy there's no eschatological component to prophetic speech or activity, which is a supplemental to judicial procedures. Anyway, wanted to get those details out of the way before getting back to the topic at hand.
Gideon was offered the kingship, arguably, because by being a military protector who organized Israel he performed one of the functions kings would have been expected to fulfill. Gideon declined and while that public refusal may seem principled that Gideon named his son Abimelech may reveal that privately, in all the ways that may ultimately have mattered, Gideon truly thought of himself as the king. It's possible to formally repudiate kingship and claim you are not the king when, in your heart and in your actions, you assume you truly are the king. Abimelech, well, he went on to slaughter his brothers and take kingship for himself and God sent an evil spirit to bring disaster on Abimelech and the Shechemites for their treachery and bloodshed. One of the things that doesn't preach so much from the pulpit is that God clearly has a history of being willing to send demonic interference to punish His people when they use deception, violence, and intimidation to get their way, particularly on behalf of corrupt leaders.
That Gideon is also referred to as Jerubaal is something Barry Webb discusses in his commentary on the book of Judges. "Let Baal contend with him" can be a bitterly ironic name because by the end of Gideon's tenure as a judge Israel is back to its old bad habits and these were facilitated by Gideon's own activity. Refusing to be the king yet setting up an idol while privately thinking of himself as actually the king reveals that Gideon may seem to have started off with some promise but by the end he led Israel back into idolatry and was willing to privately congratulate himself on being the king even if he'd publicly looked like he'd turned down the job.