For as long as he has been in elected office, Senator Bernie Sanders of Vermont has warned that the nation’s richest people have amassed too much wealth and power.

Now, President Trump sits in the White House and Elon Musk, the world’s richest person, is presiding over the firing of thousands of federal workers.

For Mr. Sanders, there is no joy in being right. He remains upset that more Democratic politicians do not seem to share his conviction that the American political system requires a radical overhaul — a sentiment that he thinks pulsed through the country last year and contributed to Mr. Trump’s victory.

On Friday and Saturday, Mr. Sanders, the longtime independent, plans to hold campaign-style rallies in Omaha and Iowa City. He hopes the two events will pressure the House Republicans who represent those areas to break from Mr. Trump when they vote next month on the federal budget.

Mr. Sanders discussed his plans, along with the Democratic Party’s current predicament and who, if anyone, is articulating an effective message against Mr. Trump. The interview has been lightly edited and condensed.

You’ve been warning about an impending oligarchy for years, and it seems as if the situation has gotten worse. Why do you think that is, and why hasn’t the country heeded the message that you have preached?