Boebert, billionaires' tax and other midterms races still to watch

Democrats have been celebrating their sweeping midterm victories, including flipping control of both chambers of Congress - but several critical races were still too close to be called on Thursday.

Votes are still being counted in two surprisingly tight Senate races in historically red states, Alaska and Mississippi, which could decide the true scale of Democrats' majority.

Several US House races are also too close to call, including that of Lauren Boebert, a prominent ally of President Donald Trump, who is facing a tight re-election contest in Colorado against Democratic challenger Eileen Laubacher.

Here are the races Americans are watching closely.

What and who are on the ballot: The race for Mississippi's Senate seat remains dramatically close with Democrat Scott Colom leading Republican incumbent Cindy Hyde-Smith by a little over 1,100 votes. The state has until 10 November to count provisional and late-arriving mail ballots.

On the campaign trail, Colom focused his message on plans to address economic concerns, while Hyde-Smith, the first woman to represent Mississippi in the US Congress, was endorsed by Trump and campaigned with him.

Why it matters: If Colom wins, he would be the first black US senator elected in Mississippi since 1875 - and the first Democrat since 1982. Mississippi is a state home to the largest percentage of African Americans in the US, a group that overwhelmingly votes Democratic and showed up in large numbers this election.

What and who are on the ballot: It's another extremely tight race being watched nationally with Democrat Mary Peltola leading Republican incumbent Dan Sullivan by just over 600 votes with more ballots to be counted.

Peltola, a former congresswoman and Native American, campaigned for "fish, family and freedom", while two-term Republican Senator Sullivan focused on his efforts to get Americans tax cuts and "unleash Alaska's energy potential".

Why it matters: The race has been marred with controversy because of the appearance of another candidate named Dan Sullivan on the ballot.

Last week, The New York Times reported allegations that Peltola and Alaska Democrats sought to confuse voters by recruiting the independent Dan Sullivan in order to siphon votes from the Republican Senator Dan Sullivan. Peltola has denied any knowledge of such a scheme.

What and who are on the ballot: Trump ally Lauren Boebert is trailing Democrat Eileen Laubacher by a narrow margin in Colorado's Fourth District with 7% of votes left to be counted. In Tennessee's reliably Republican Fourth District, Representative Scott DesJarlais is trailing Democrat Victoria Broderick. In Arizona's Second District, incumbent Republican Eli Crane is leading Democrat Jonathan Nez by fewer than 4,000 votes with still many to be counted.

Why it matters: A loss for Boebert, DesJarlais and other Republicans in House races in Nevada and Ohio would mean an even larger majority for Democrats in the chamber - and a bigger rejection of Trump and his Make America Great Again movement.

What and who are on the ballot: California Proposition 40 would require a one-time 5% tax on the net worth of the state's roughly 200 billionaires to raise tens of billions of dollars in revenue. As of Wednesday, a million more people had voted against the measure than in favour, though only 61% of votes have been counted.

Why it matters: The measure would mark the first-ever wealth tax on billionaires in the US, which proponents say would raise $100bn for health care and education. But the proposition divided Democrats, with Governor Gavin Newsom opposing it.

What and who are on the ballot: For Kansas's next governor, Democrat Cindy Holscher is leading Republican Ty Masterson by a few thousand votes.

Holscher campaigned over escalating prices, while Masterson touted his pro-business, pro-agriculture, and pro-oil and gas credentials.

Why it matters: For more than 50 years, Kansas has elected governors from the opposite party of their predecessors. If Masterson wins, that trend would continue. Holscher's victory would break it by putting another Democrat in office after two-term Governor Laura Kelly.

• LIVE UPDATES: All the latest developments
• RESULTS: How America voted in maps and charts
• EXPLAINER: Five reasons why Trump did so badly
• ZURCHER: Midterm carnage weakens Trump but he still wields power for now
• ANALYSIS: Vance walks Trump tightrope with scathing election critique blaming Iran war
• REACTION: Angry Republicans blame Trump for midterms 'disaster'
• NEWSLETTER: Sign up for Anthony Zurcher's analysis in your inbox