Its a campaign truism. The way out for Republicans at risk because of Trump is to change the subject and attack Clinton.
That helps minimize, they hop the downside of Trump, and riles up the base into voting. Maybe, although its not clear that the base needs any more riling up.
The unrecognized problem — and I think it may be a big problem strategically — is that the less generally Republican leaners can imagine voting for Clinton, the less they will consider voting and ticket splitting, and the more they will prefer to just stay home.
If your plan is to rely even in part on ticket-splitting, and its hard to imagine any even slightly endangered Republican not having a strategy that relies at least on ticket-splitting, then you are doing exactly the wrong thing.
If down ballot Democrats do better than expected this year, this may be one of the reasons.
Of course, the other strategy is to endorse Clinton, but that has its downsides too. Its tough this year!