I don't know whether it is true that that individual tea party protesters have used racists and homophobic epithets against Democratic lawmakers (see for example this report by Politico's Kenneth Vogel and this report). But even if it is true, Democratic leaders should have a muted reaction and should not attempt to use this for political gain.
There is no doubt that this health-care debate has been contentious and in many instances quite ugly. All sides have tried to gain whatever political advantage that they can by using the perceived missteps of their opponents for political gain. If is true that tea party protesters aimed slurs at lawmakers, it would be tempting to describe and dismiss the tea party movement as racist and anti-black. But that would be a serious mistake.
First, some tea party leaders dispute the contention that their adherents engaged in racist name-calling. Second, and perhaps most importantly, this is not the way the movement's leaders view the organization and themselves. Third, assuming that some individuals associated with the movement are in fact racists, we should not tag the whole movement with the actions of most of its fringe elements. Fourth, we harm the cause of racial justice by using race in such a crass and instrumental way.
I wonder if the people who would dismiss the tea parties by calling them racists really care about racial justice as a first-order priority or whether this is a political move meant to silent and discredit a political opponent. If the tea party is truly a racist movement, then we should confront that issue head-on and we should not be afraid to call it so. If however, the tea party movement is at best afflicted by rogue individuals racists, it is wrong to attribute the views of these individuals to the movement. This is especially true when it seems that the movement's leaders are attempting to remove racists from their midst and reject instances racism where those are evident among some of their members.
It goes without saying (therefore, I will say it), given the importance of having productive political discourse in this country, we should be very careful to dismiss those with whom we disagree politically as racists, unless we are sure that they truly are racists. Racism is such an incendiary charge that Democratic leaders should not fan the flames or take political advantage because the charge might completely corrode our political discourse.