As the 2024 election season approaches its final week, Democrats are fighting hard to retain control of the U.S. Senate. The party is defending its seats in tight races across the country — and it has little to no room for error.

Their slim hopes in the upper chamber of Congress — the gatekeeper of substantive legislation and responsible for confirming Supreme Court justices and top presidential administration appointees — may hinge on their hopes of unseating Sen. Ted Cruz in Texas.

Texas is certainly not a place where Democrats put their trust. No Democrat has won a contest there in three decades. The Lone Star State seems constantly out of reach for Democrats, raising their hopes only to resoundingly dash them on Election Day.

The Texas government has pursued a steady stream of right-wing policies on immigration, abortion, education and other sensitive cultural issues. The last Democratic presidential candidate to win there was Jimmy Carter in 1976.

Cruz has served two terms and has had a nationwide support network since his bid for the Republican presidential nomination in 2016. With the support of evangelical voters, he won the Iowa caucuses this year, finishing second to Donald Trump.

The former corporate lawyer and Supreme Court clerk has developed a reputation in the Senate as a conservative hothead who pushes for government shutdowns to advance his policy priorities and often engages in heated exchanges at committee hearings and media appearances.

Despite all this, Democratic presidential candidate Kamala Harris is in Houston on Friday, holding a rally with the party’s Senate candidate, Congressman Colin Allred.

And for the first time this campaign, she will appear alongside pop star Beyoncé, who will perform at the city’s Major League Soccer stadium.

Just over a week after Election Day, it is a remarkable investment of valuable time and resources. However, opinion polls show a tight race between Allred and Cruz – within the margin of error in some polls and significantly closer than the contest between Harris and Donald Trump in the state.

Allred, a three-term congressman from the Dallas area, is a former NFL player and college football standout at Baylor University in Waco, Texas. He worked in the Obama administration before running for public office and presents himself as a moderate politician.

Meanwhile, for all his political strengths, Cruz is not universally popular, even in conservative Texas. In his re-election in 2018, he defeated Democrat Beto O’Rourke by less than 3%.

And in 2021, he faced criticism for traveling to Cancun, Mexico, while much of Texas was experiencing power outages due to a record-breaking winter storm.

The duel is enough to give the Democrats hope again.

At the Cactus Jack Cagle Community Center in Spring, Texas, a steady stream of Texans gathered Thursday afternoon to vote early in the Nov. 5 election. Many said they would support Trump and Cruz, particularly because of the economy and their views on limiting illegal migration. But those who supported Harris in this northern Houston suburb were cautiously optimistic.

“Cruz is wishy-washy,” Leona Fuller said. “He called Trump all sorts of names (during the 2016 presidential campaign), and now he’s suddenly pro-Trump. You can’t do that and expect to lead people and be effective in your leadership.”

Floyd Guidry III, voting for the first time since he was 18, said he wrote a school report on Allred’s policy proposals and was particularly drawn to his calls for criminal justice reform.

“It’s time for change,” said Floyd’s father, who accompanied him to the vote. “It doesn’t matter if you’re a Republican or a Democrat.”

However, many political experts have doubts.

Miles Coleman, co-editor of Sabato’s Crystal Ball at the University of Virginia’s Center for Politics, rates the race as “likely Republican.”

“Texas will be a mess state one day,” he said, citing changing demographics as the state becomes younger and more diverse. “But I don’t think it’s going to happen for Democrats this year.”

But if Democrats want to retain control of the Senate, opportunities to do so are few and far between.

They currently have 51 seats in the 100-member chamber. If they win the presidency (a big gamble), they can only afford to lose one seat. If Trump wins, any net loss for the party would leave the chamber to Republicans, with Vice President JD Vance providing a tie-breaking vote.

The map for Democrats this year is bleak.

This year, 34 of the chamber’s 100 senators are up for election with six-year terms. Democrats are defending 23 seats – partly the result of the party’s above-average performance in 2018 and 2012.

Trump won significantly in three of these states – Ohio, Montana and West Virginia – in 2016 and 2020.

Centrist former Democrat Joe Manchin’s vacation of the West Virginia seat is effectively a lock on the Republican handover. In Montana, three-term incumbent Jon Tester has been behind in the polls for months.

Five other Democratic-controlled seats are in states considered contenders in this year’s presidential race: Pennsylvania, Michigan, Wisconsin, Arizona and Nevada. In three of those states, Democratic incumbents are seeking re-election. In the other two cases, a new candidate attempts to replace an outgoing senator.

Now, most of the Republican-held seats on the ballot are in deeply conservative states like Mississippi, North Dakota and Wyoming. Only in Florida and Cruz’s Texas are the Democrats even remotely within striking distance.

In another state, reliably conservative Nebraska, an independent candidate – Dan Osborne – is in a tough race with Republican incumbent Deb Fischer. However, it is not certain whether Osborne would vote to give Democrats a working majority if he won.

“Sometimes in safe states you have incumbents who get lazy,” Coleman said. “Deb Fischer hasn’t had a tough race since she was first elected.”

Of greater concern to Democrats is the fact that only once in the last two presidential election years — in Maine in 2020 — has a state voted for a president of one party and a senator of another party.

If this trend away from ticket splitting continues, Mr. Coleman said, Democrats have little hope. This could explain why the party is dedicating more resources to incumbents in battleground states rather than supporting challengers in Republican-friendly Texas and Florida.

This week alone, the Democratic Senate majority leader’s political action committee spent more than $15 million (£11.5 million) on advertising for the Ohio and Pennsylvania races. $60,000 was spent in Texas.

“If you look at how Democratic groups spend their money,” Mr. Coleman said, “they are more interested in maximizing the number of seats they could hold after the election than in maximizing their potential targets.”

The money that the party has so far flowed to Texas is only a “drop in the ocean” in such a large state.

What are Harris – and Beyoncé – doing in Texas then? According to Mr. Coleman, it gives Democrats a chance to shift the national focus to the state’s strict anti-abortion laws – an issue on which polls show the party has a significant advantage over Republicans.

And even if Allred doesn’t win, a strong showing against Cruz could help the state’s Democratic Party build an infrastructure that would allow it to be more competitive in the future.

That may not be what Texas Democrats hoping to win this year or party loyalists hoping to stay in the Senate want to hear.

But it could be the cold, hard reality the party faces as Election Day approaches.

North America correspondent Anthony Zurcher breaks down the race for the White House in his twice-weekly newsletter, US Election Unspun. Readers in the UK can Register here. People outside the UK can do this Register here.