Lawmakers in the US House of Representatives have broken with a practice that goes back a century. They failed to elect a leader of their chamber on the first ballot. And, after six rounds of voting, they are still divided.

Republicans won a majority of House seats in midterm elections in November. So they should be able to determine who will take the gavel as speaker. But hardline conservatives have refused to get behind the party's House leader, Kevin McCarthy.

They are demanding changes to House rules, to the leadership structure and even to the federal budget. Their opposition has prevented McCarthy from getting the votes he needs.

President Joe Biden said having a Congress that cannot function is "just embarrassing."

Former President Donald Trump is calling for unity. He gave his endorsement during the midterms to most of the Republicans who are opposed to McCarthy. But he took to social media to tell them not to turn a "great triumph" into a "giant and embarrassing defeat."

The House cannot operate without a speaker. Members cannot be sworn in, debate legislation or carry out other duties they were elected to perform. And some Republicans say the fight could drag on for weeks.