Kast Approval Falls to 25% in Chile’s September Survey, 11 Points Below August

CHILE · POLITICS

One pollster, one question, five monthly readings — and a fall that looks different once you see the whole line.

Kast approval fell to 25% in the September Data Influye survey in Chile, down from 36% in August. The same poll put disapproval at 62%, the highest in this pollster’s own series.

What the September Kast approval poll found

Data Influye is produced by the Chilean firm TúInfluyes.com, which funds it. The September wave was published on 23 September 2026.

Fieldwork ran from 17 to 21 September 2026. The firm completed 1,216 interviews with adults across 194 communes.

The questionnaire was self-administered online, drawn from a non-probability panel rather than a random sample. Data Influye reports a margin of error of 2.8 points at 95% confidence.

That margin assumes simple random sampling, which an opt-in panel is not. So treat it as a guide rather than a guarantee.

The survey put Kast approval at 25%, disapproval at 62% and 13% who neither approve nor disapprove. The government as a whole scored 24%, down from 33% in August.

The only fair comparison is Data Influye against itself

Comparing a poll with itself over time is the cleanest test available. Same firm, same question, same method, month after month.

Data Influye asks how people rate the way Kast is conducting his government. The wording has held steady through the year.

Its readings run 26% in May, 30% in June, 29% in July and 36% in August. The September figure of 25% is the lowest of the five.

Disapproval tells a steadier story: 54%, 58%, 56%, 61% and now 62%. That line has climbed in almost every month of the series.

Why the 11-point fall is smaller than it looks

The 11-point drop is measured from August, and August was the odd one out. It sat seven points above July and ten above May.

Measured against July’s 29%, September is four points lower. Measured against May’s 26%, it is one point lower.

One point is well inside the stated margin of error. The new low is real in the table, but it is thin as evidence.

A fairer summary: this pollster has had Kast in the mid-to-high twenties since May, bar one higher month. The August jump is what needs explaining.

Sample sizes also move between waves. The firm reported 1,136 cases in May, 1,002 in July, 952 in August and 1,216 in September.

Why mixing pollsters creates a false trend line

Two other firms published readings on Kast this month. Criteria had 29% on 20 September, and Cadem had 35% on 16 September.

Those numbers are not points on the same line as Data Influye’s. Each firm uses its own sample, mode, wording and field dates.

Stringing 35%, 29% and 25% together looks like a collapse inside one week. It is three readings from three different instruments.

The gaps between firms are often wider than the movement inside any one of them. A single-series trend deserves more weight than a blended one.

What is driving the numbers

Respondents named inflation and the cost of living as the main problem weakening the government, at 30% of mentions. Kast’s leadership style came second at 19%, and unemployment third at 16%.

On performance, 58% said growth and jobs had gone backwards, and 56% said the same on inflation. Control of irregular migration scored best, at 25%.

The hard numbers behind the mood are public too. The national statistics institute (INE) put unemployment at 9.5% for May–July, a five-year high.

Fuel costs are the other sore point. In late March the finance ministry passed through a rise of 370 Chilean pesos (US$0.39) a litre on petrol.

Diesel rose by 580 pesos (US$0.61) a litre. Those dollar figures use about 948 pesos to the dollar at 23 September 2026 rates.

What the government says

Kast blamed the fuel rise and unemployment when asked about earlier polls on 14 September. He said one has to speak the truth, “and the truth hurts”.

Officials at La Moneda told BioBioChile that surveys are watched and analysed but do not change the government’s course. Another said this was always the year of difficult decisions.

The week brought another setback. On 23 September deputies rejected a reform to extend detention of migrants facing expulsion.

Kast said he regretted the vote and would keep pushing the measure. He said those who voted against or abstained would have to explain themselves.

Why this matters for expats and investors

Approval numbers do not move markets on their own. They matter because they shape what a government can pass, and how quickly.

A president polling in the twenties has less room to push contested bills through Congress.

For residents, the practical effect is usually slow rather than sudden. Tax, pension and labour changes take longer, and timetables slip.

For investors, the habit that helps is to follow one pollster’s line. A second low reading from the same firm would matter more.

What is not known is whether August’s 36% was a genuine rise or a wobble in the panel. Data Influye does not publish enough detail to settle that.

The next wave is due in late October. Until then, the fair statement is that one pollster has Kast approval at its lowest, by a single point.

More: Chile news in English, every day from The Rio Times.

Frequently Asked Questions

What is Kast’s approval rating in the September Data Influye poll?

Data Influye put Kast approval at 25%, with 62% disapproval and 13% neither approving nor disapproving. Fieldwork ran from 17 to 21 September 2026.

Is 25% really his lowest reading?

It is the lowest in this pollster’s own series, which read 26% in May 2026. The gap is one point, inside the stated margin of error.

Why not compare it with the Criteria and Cadem polls?

Those firms use different samples, methods, wording and dates. Their numbers sit on separate lines, so blending them creates a trend that does not exist.

Sources: Data Influye (TúInfluyes.com) September 2026 survey, fielded 17–21 September 2026; Chile’s National Statistics Institute (INE), 28 August 2026; BioBioChile; CNN Chile; T13; El Mostrador; Publimetro; Radio Universidad de Chile.