Verdict: Opinion. The claim does not define a time period or a measurable meaning of “becoming socialist,” and the approved surveys show mixed evidence rather than a demonstrated trend.
Democrat party base is changing to socialists
The Claim
Democrat party base is changing to socialists

FactVerify
Source: factverify.com
Key Evidence
In a 2022 Pew survey, 33% of Democrats said they liked political leaders who identified as democratic socialists, while 18% said they disliked such leaders.
Pew reported on September 19, 2022, that these views were essentially unchanged over the prior year.
Gallup reported in August 2018 that Democrats’ positive views of socialism had not changed materially from 2010 to 2018.
What the Evidence Shows
What is established
A 2019 Pew survey found that 65% of Democrats and Democratic-leaning respondents had a positive impression of socialism.
Context and caveats
The claim does not specify whether “socialists” means people with positive views of socialism, supporters of socialist-identified leaders, or people who self-identify as democratic socialists; those measures are not interchangeable.
The supplied evidence does not establish a statistically tested trend across comparable surveys or election cycles.
A partisan article attributed a claim that one-third of Democrats identify as democratic socialists to a CNN poll, but the supplied evidence does not include that poll’s methodology, wording, field dates, or primary report.
The available evidence does not determine whether Democratic voters’ self-identification as democratic socialists has increased over time.