Republicans failing to secure Senate seats along the U.S. border, polls suggest

With the elections less than 100 days away, Republicans and Democrats alike are keeping their eye on certain congressional races that will likely determine who will win control of both chambers in November.

Republicans predicted they would win big across border states in the Senate, given how immigration has become a perceived political vulnerability for some Democrats. However, in Arizona, New Mexico and California, polls suggest Democratic Senatorial candidates to be leading in their respective territories.

One of those races has gained national attention from the press. In Arizona, former television anchor and Trump-ally, Kari Lake will face off Rep. Ruben Gallego, who both won their spots on the ballots last week in a slate of primary elections.

Both parties are optimistic about their chances with these candidates. As Vice President Kamala Harris steps up to the Democratic nominee and the GOP goes on the offense on immigration, dubbing her as the "border czar," they believe Lake could gain momentum. Democrats, on the other hand, are hoping Gallego will be able to appeal to moderate voters and Republicans tired of Trump-ism in the state.

Lake has been trailing Gallego on the polls throughout the campaign season. For instance, a HighGround poll concluded on Aug. 5 showed Gallego beating Lake 50% to 39%.

Another Emerson College poll found Gallego leading Lake by four points (46% to 42%). The poll surveyed 800 Arizonans on July 22-23 and has a margin of error of plus or minus 3.4 percentage points.

A similar outcome is also seen in New Mexico, where Nella Domenici, the Republican daughter of a former U.S. Senator and Martin Heinrich, the Democratic incumbent in the Senate are heading face-to-face.

That contest is facing increasing tension, with Heinrich recently launching an ad campaign questioning whether Domenici is a true New Mexican, having lived a large portion of her life in the east coast and working in Wall Street.

In the recent attack ad, Heinrich's campaign claims, "Nella [Domenici] hadn't lived in New Mexico since 1973, back when Richard Nixon was president...Wall Street's got enough senators. We need one who will fight for us."

This narrative seems to be working, as a Redfield & Wilton Strategies survey shows Heinrich leading by 40% compared to Domenici's 34%. An earlier poll in June showed similar results, with Heinrich winning the race with 46% compared to Dominici's 42%, according to FiveThirtyEight Interactives.

In California, the contest's gap seems to be much wider between Democratic Rep. Adam Schiff, and Republican candidate and former L.A. Dodgers star Steve Garvey. The race is considered to be a once-in-decades opportunity to replace the late Sen. Dianne Feinstein, and the winner could hold onto the seat for years to come.

Schiff seems to have started the race with a large advantage. An early-July poll by the Public Policy Institute of California showed the Democratic candidate leading 64% compared to Garvey's 33%. Another early-June poll from the same institute showed Garvey trailing behind Schiff 37% to 62%.

The data comes as Harris and Democrats continue to gain momentum ahead of November. For instance, Harris is expected to have surpassed former president Trump in the polls in Arizona, a key battleground state for these elections, The Hill reports.

"Now that the primary is over, things are starting to come into focus. As the newly minted Presidential nominee, Vice President Harris is starting off with a narrow but notable lead," Chuck Coughlin, president and CEO of HighGround Inc, said in a statement. "It's a good start, but with the attacks already starting, we expect some rough patches ahead."