As constitutional scholars digest the [Supreme Court's latest decision freeing donors to spend more money on campaigns], it has already set off a bipartisan scramble for campaign cash, thrusting party leaders, lawmakers with leadership PACs, and candidates into a fierce competition. The ruling allows donors to make the maximum contribution to an unlimited number of campaigns, freeing donors from caps that required them to pick and prioritize from among each party's candidates and national committees. And while the decision could inject tens of millions of additional dollars into the 2014 races, it has also left some candidates and party leaders with a new concern: that the biggest donors will get tired of writing new checks. Fund-raisers and donors in both parties said they had begun to get a wave of tentative and not-so-tentative requests for new checks or future commitments, as the leaders of the parties' congressional wings compete with each other and with the Republican and Democratic National Committees. All are focusing on a relatively limited group of donors in both parties who appeared to have given the maximum allowed or come close to the old cap - the people most likely to write additional checks after [the court's] decision.