WASHINGTON (AP) — The House Freedom Caucus has been on its best behavior these past few months. The group of about three dozen hard-right Republicans has a penchant for fighting with GOP leaders over tactics and strategy, and helped topple Speaker John Boehner, but it has played nice in the party's drive this fall to cut taxes.

Not anymore.

Washington's agenda has shifted to the budget, immigration and other contentious issues — and that has set off alarm bells inside the Freedom Caucus, which fears being on the losing end as GOP leaders and President Donald Trump by necessity turn to Democrat...