SIOUX CITY, Iowa — Hillary Clinton's last pitch to rural Iowans before Monday's caucus featured attempts to maneuver to the left of Sen. Bernie Sanders on economic and fiscal issues.

The former secretary of state's competition with Sanders, a Democratic socialist, for the Democratic presidential nomination appears largely responsible for her decision to emphasize combating Wall Street and taxing the wealthy while in Iowa.

Clinton has criticized the cost of Sanders' plan to provide free healthcare and college education for all — estimating that it nears $20 trillion total. But in western Iowa on Sunday, Clinton promised she would make college affordable by raising taxes on wealthy Americans. And she struck a populist tone to drive the point home.

"I am the only candidate on either side, Democrat or Republican, who will make this pledge to you: I will raise your wages, not your taxes," Clinton said. "I will not raise middle-class taxes."

But Clinton talked up her plan to raise levies on wealthy Americans. She touted a plan to impose a 4 percent "fair-share surcharge" on incomes above $5 million. "If you make a million dollars you should pay a 30 percent effective tax rate," she said.

Clinton also sought to blunt Sanders' Wall Street reform proposals by noting that she wants to go further to "prevent the shadow-banking sector from wrecking our economy."

"I went to Wall Street long before this became an issue and told them they were wrong to be hurting us unless they changed what they were doing," Clinton said. "I have no grief for what they did. And I will do everything I can to make sure they don't ever do it again."

Sanders has noted that Clinton has profited from some of those same Wall Street banks. Goldman Sachs reportedly paid Clinton $675,000 for three speeches she gave. She also raked in cash from Morgan Stanley and Deutsche Bank through speech fees.

Such facts have contributed left some Clinton supporters short on enthusiasm.

Mary Streker, who plans to caucus for Clinton in Le Mars, called Clinton the pragmatic choice. Streker said she is concerned that a Sanders candidacy could damage the Democratic Party's ability to regain control of Congress.

"Bernie Sanders kind of has my heart, and there was a day where I wouldn't consider voting for anybody but my heart," Streker said. "But there's so many practical aspects about it. I think one of the most important things I'm concerned about is what Bernie Sanders would do to the down-ticket. And if you look at that, there is no comparison."

Rich Pope, who will caucus in Sergeant Bluffs, said he is leaning toward Clinton but he might change his mind on Monday.

"As my first choice, I will sign in the door as a Hillary person, probably," Pope said. "But we're Iowans, you know? We get to decide at the last minute."