All nominees do extensive background checks on their prospective VP candidates for that very reason, including tax returns. If the Rules committee enacts this change, Trump will likely whine and complain about it. As Trump cooked up scheme after scheme on his own, it is unlikely he would have refrained from participating in these. So, Republicans, if you want to be rid of Trump, institute this rule. If Republicans want to rid themselves of Donald Trump without ignoring the primary results, the only way to do that is for Trump to bow out on his own.
Source: Huffington Post July 05, 2016 15:11 UTC