Republicans are running the midterms against socialism, which is good news for a left that is more popular than it has been in decades and bad news for Democrats caught in the middle.

• Socialism just got its first positive rating in Gallup polling, at 40%.
• Trump and Republican ads are leaning hard on socialism and communism warnings to blunt an expected blue wave.
• A century ago the movement was strongest in the heartland — Oklahoma, Kansas, Milwaukee, mining towns — with 1,200 local officials but never more than 6% in a presidential race.
• Today's version is the reverse: big national names like Bernie Sanders, AOC and Zohran Mamdani, but thin roots and a base of college-educated nurses, teachers and tech workers rather than warehouse workers.
• That gap is the movement's main weakness, and without a strong labor movement behind it the national popularity may not translate into power.

Outlook: Expect socialism to stay the central Republican attack line through the midterms, while the left's test is whether it can reach blue-collar and service workers beyond big coastal cities.