As I recall, both Sarah Palin and Mitt Romney campaigned for Joni Ernst.
People need to stop worrying about things that don’t matter and worry about things that do.
Ernst is an interesting case. Palin didn’t really know her when she endorsed Joni (seems like a a Gyno-American deal to me). Romney has known her for a number of years, and didn’t just endorse and make an appearance or two; he furnished her with staff and money.
That did not stop Joni from taking a resolutely pro-life stand, nor did it motivate her to back away from her Second Amendment stand.