PHOENIX Independent Sen. Kyrsten Sinema of Arizona announced Tuesday that she wont run for a second term after her estrangement from the Democratic Party left her politically homeless and without a clear path to reelection.

Sinemas announcement comes after Senate Republicans blocked a bipartisan bill to help secure the border and deliver military aid to Ukraine and Israel, which Sinema spent months negotiating. Shed hoped it would be a signature achievement addressing one of Washingtons most intractable challenges, as well as a powerful endorsement for her increasingly lonely view that cross-party dealmaking remains possible.

But in the end, Sinemas border-security ambitions, and her career in Congress, were swallowed by the partisanship that has paralyzed Congress.