Putting the RNC's Spend-O-Meter to the Truth-O-Meter test, we find the Republicans are doing a reasonably good job of accounting for Clinton's spending proposals. In 19 out of 24 examples cited by the RNC, the Spend-O-Meter correctly explained Clinton's proposals.
However, in one case, the RNC includes $80-billion baby bond proposal that Clinton quickly dropped after talking about it. Since Clinton never formally proposed the idea, you can subtract $80-billion from the $777.6-billion.
We realize the RNC had to make some assumptions to keep the arithmetic simple. For instance, their calculations assume that each program becomes law at the very start of Clinton's first term, allowing the Spend-O-Meter to add things up over four full years. Of course, it can't really happen that way, but for purposes of keeping tabs on the cost of Clinton's proposals it's within reason. It's also true that the RNC doesn't note that some of Clinton's proposals, already in legislation in Congress, have drawn the support of some Republicans.
Still, as gimmicks go, this one stays close enough to the facts to rate a Mostly True.