Yes, Donald Trump may hurt the GOP Senate candidates in the election this November. Donald trump's views are very controversial and not as neutral as most of the GOP candidates. These candidates will be held responsible for the things that Trump says and will lose votes as a result of his comments.
Donald Trump will hurt the GOP Senatorial candidates this November. His rhetoric is hurting his chances, and people will be afraid a Republican Congress will go along with him out of party loyalty. His candidacy may also inspire a greater turnout among Democratic supporters that will vote along the party line.
Donald Trump has caused the Republican Party to seriously reexamine both its priorities and public image. While several members of the Party elite have disavowed "the Donald," this isn't enough to protect GOP Senate candidates come the November election. Trump's campaign and candidacy have forever marred the Party in the eyes of voters.
There are many Republican voters who do not support Donald Trump. There are also several Republican politicians who have distanced themselves from him. The senate candidates can speak out against Trump if they do not support him and it will not hurt them in their state elections. They can run their own campaign.