How will the mass shootings impact the presidential race?

Well clearly it makes gun control more of an issue for Democrats. But more broadly, they'll take the case directly to President Trump as Beto O'Rourke did over the weekend blaming his rhetoric and actions for an increase in hate and violence in the country.

Will there be gun control legislation after these attacks?

No, there won't. There hasn't been after any of the other recent attacks which happened over and over and this time will be any different.