I don't think it's him prioritizing politics over family.
I think it's that he was taking her for granted that she was a perfect wife and mother, but most of all that he didn't even seem aware of it.
He couldn't even give her the respect of acknowledging her situation and treating their marriage as the political arrangement that it was, and instead did that wishy-washy attempt at acting like a "good and caring husband" when he did no such thing for the weeks preceding her falling ill, by saying "After all, you're my wife".
He didn't prioritize politics over his family. He prioritized his appearance of being a hard-worker over properly delegating duties (because those inspections and meetings weren't happening when he was in the capital, so he must have been delegating them when away from his domain) and properly acting like the warden of a political prisoner OR a loving husband.
Instead of being a warden, who Eleanor could respect, or a husband, she could love, he was incompetent at being either one.