Holman Jenkins at the Wall Street Journal took a look at Donald Trump’s finances over the weekend, and suggested the outspoken billionaire might not be able to afford to keep a serious national campaign going past the first few states: None of his offenses against propriety seem to have dinged the support that, in a crowded race, keeps Donald Trump atop the GOP primary polls. Republicans are now talking about a brokered convention, which could be a disaster for the country, and for the GOP, and quite possibly hand the election to Hillary Clinton without a real contest or even...