Tense Tuesday as Democratic Rivals Battle Over Midwest... and Momentum

As voters turned out for the next round of presidential primaries in five states on Tuesday, Bernie Sanders is aiming for a possible set of Michigan-esque victories in the key mid-western states of Ohio, Illinois, and Missouri.

The polls show that "this is about as close as it can be for us," Sanders' campaign manager Jeff Weaver told backers on Tuesday, noting that the senator is running five percentage points ahead of Clinton in Ohio, three points ahead in Illinois, and tied in Missouri, according to recent survey results from Public Policy Polling.

Also voting today are Florida and North Carolina, where Sanders continues to trail Clinton. The Sunshine State has the most delegates up for grabs with 246 for Democrats.

There are 182 delegates in Illinois, 84 in Missouri, 121 in North Carolina, and 159 in Ohio. "As in all Democratic primaries, the margin is key because delegates are awarded proportionally. But really, who knows what will happen," writes Harry Enten at FiveThirtyEight.

According to The Hill:

It's possible Clinton could still win more delegates even if Sanders wins all three states, by keeping the margin close and winning big in Florida and North Carolina. But the loss of Ohio, in particular, would raise questions about her candidacy. It would also give Sanders first-place finishes in seven of the last 11 contests.

Sanders has continued to galvanize the anti-establishment enthusiasm that took him from dark horse to potential frontrunner since he announced his candidacy last summer. During a rally in Akron on Monday, he denounced Clinton's history supporting trade policies that proved disastrous to the U.S. manufacturing sector.

"When the choice was made whether to support workers or corporate America, she made her choice," he told the crowd. "I made a very different choice."

Sanders held four rallies among his three best states on Monday. In St. Charles, Missouri, he said, "Despite the fact we work the longest hours of any people in the industrialized world, despite all of that effort, 58 percent of all new income created today goes to the top 1 percent. That's a rigged economy."

And in Chicago, he said, "This is the wealthiest country in the history of the world. We should be rebuilding our communities and making sure our kids have decent schools, not shutting them down."

The senator also got a boost on Monday from the Amalgamated Transit Union (ATU), the largest U.S. and Canadian transit workers' union, which praised his commitment to "the 99 percent of America that has been left out of the mainstream public debate, cheated out of our jobs and denied the true meaning of the American dream," as ATU president Lawrence J. Hanley said.