Party perpetuation trumps service to the constituency
Politicians now spend as much as 80 percent of their work time soliciting donations. Their loyalty is to their party, to which they owe their elected positions. Political careers come and go in the blink of an eye; the party goes on in perpetuity.
While the bulk of contributions to Congressional campaigns are from individual donors in amounts below $200, such donations account for a small percentage of the millions of dollars candidates raise and spend to be elected, according to figures compiled by OpenSecrets.org. For example, in the 2012 election cycle, small donations from individuals represented 11 percent of the money raised by House Democrats, 11.5 percent raised by House Republicans, 14.3 percent raised by Senate Democrats, and 7.9 percent raised by Senate Republicans.
As Reuters' Andy Sullivan reported in June 2013, members of Congress spend as much as half their workday -- and sometimes more -- soliciting donations from the rich. The impact of the time spent hustling for campaign contributions goes far beyond the time Congress members are unable to spend dealing with their constituents and conducting the actual business of legislating. Those rich donors maximize their access to legislators, filling the politicians' ears with their concerns, which usually boil down to how the politicians can help them preserve and grow their wealth ("Help my business, don't raise my taxes!")
Like all professions, politicians have limited "bandwidth" and must expend their time and effort judiciously. They may be aware of the negative impact of non-stop fundraising on their ability to do the job they were elected to do, but they likely justify the money solicitations as a requirement of the job. After all, if they can't get elected, they've got no job at all. The people best served by the current state of political financing are the financiers themselves. In fact, some would argue that they are the only people served by the current state of political affairs.