Vermont Sen. Bernie Sanders is trying to build on a burst of momentum for his presidential bid in Iowa with a four-stop bus tour in the state.

Sanders’ swing Tuesday comes as the Democratic race in Iowa tightens less than two weeks before the state’s lead-off caucuses. Sanders appears to also have an edge over Hillary Clinton in New Hampshire, which votes second.

The Democratic race has become increasingly heated in recent days.

Eager to blunt Sanders’ rise, Clinton has accused the senator of flip-flopping on guns and also called his health care proposal expensive and unrealistic.

Meanwhile, Sanders has cast Clinton as being cozy with Wall Street and, therefore, unwilling to take steps to crack down on financial practices that hurt middle class Americans.

(AP)