There has been a lot of speculation about the effect of "new media" on politics, but we don't have much information. This isn't just because of the difficulty of establishing causation--most surveys don't ask people where they get their news, so we don't even know that much about the association between news source and political views. A Washington Post/Univ. of Maryland survey from December asked about main sources of news--it gave a list of possibilities and asked people to choose all that applied--and also asked if they thought Trump's election in 2024 was legitimate, if Biden's election in 2020 was legitimate, and if there was "solid evidence that there was widespread voter fraud in the 2024 election." The voter fraud question is particularly interesting because it doesn't have an obvious connection to partisanship: Trump talked about the likelihood of fraud before the election but treated the results as accurate after he won, while the Democrats expressed more confidence before but had reason to be unhappy with the results.
Overall, 79% said Trump's election was legitimate, 63% said Biden's election had been legitimate, and 16% thought that there was solid evidence of fraud in 2024. I took the percentages who held these views for each news source and constructed two variables--Trump's election was legitimate minus Biden's election was legitimate, and Trump's election was not legitimate plus Biden's election was not plus there was widespread fraud in 2024.* The first variable can be taken as left/right orientation and the second as cynicism about the political process. The figure shows the relationship between these two variables:
The blue dots are new media and the red ones are traditional media.** The audiences of the new media are higher in cynicism, but scattered across the right/left spectrum. The audiences of the traditional media cover a wide range in both dimensions, but there is a strong pattern--audiences that are farther to the right are also more cynical. To make it more concrete, among people who said they got news from "The New York Times or another national newspaper" 86% said Trump's victory was legitimate, 90% that Biden's was, and 4% that there was widespread fraud; among those who got news from Fox, 81% said Trump's victory was legitimate, 41% that Biden's was, and 23% that there was widespread fraud. That is, the Fox audience was more likely to choose the cynical answer on every question, even Trump's victory. There was no such pattern with the new media.So this evidence suggests that the main effect of the new media is not to move people to the left or right, but to reduce confidence in the political process. Of course, some of this is selection, but probably not all of it--people choose sources that are in line with their views, but then those sources reinforce those views.
*I standardized the underlying variables first so they would have equal influence.
**Note that I don't say "legacy media." Use of that term is a pretty reliable sign that someone doesn't know what he/she is talking about.