The Democrats' central party had seen its debt swell to almost $23 million last year. [...] the DNC has paid off its bank loans and now owes less than $2 million to vendors. Senate Democrats' campaign arm outraised its GOP rival again last month and now has $32 million saved to help endangered incumbents defend their narrow majority. House Democrats' uphill effort to oust Republicans from their majority is sitting on a $56.7 million pile of cash heading into what is shaping up to be a costly fall election season. Despite heavy spending, Republicans are expected to hold onto their House majority after November's elections due in large part to redrawn congressional districts that have left few competitive races.