Tillis risks being viewed as a Trump antagonist due to his repeated criticisms, with less friendly Republicans welcoming his willingness to buck the White House.
The potential 2028 presidential candidates showcased a Democratic midterm strategy that would assail G.O.P. votes in favor of cutting Medicaid and allowing health care subsidies to expire.
As the F.B.I. has added payback to its portfolio, Republican lawmakers like Senator Charles E. Grassley have emerged as a clearinghouse for leaks and whistle-blowers.
The president urged Representative Julia Letlow of Louisiana to run against Mr. Cassidy, in a move that is likely to further complicate his relationship with Senate Republicans.
The first veto of the president's second term killed legislation that would have brought clean water to some of the most conservative parts of the state. Residents wonder why.
Republicans, who haven't won a statewide race in Minnesota in two decades, see a moment to break through. But there are still many factors stacked against them.