5 Reasons Why the Race Between Hillary Clinton and Bernie Sanders is Tightening The race for the Democratic Party’s nomination is tighter than ever.

 -- The race for the Democratic Party’s nomination is tighter than ever. Back-to-back polls appear to show Vermont Senator Bernie Sanders with the momentum, gaining ground and even passing Secretary Clinton among likely caucus-goers in Iowa.

A new Bloomberg/Des Moines Register poll out today had the two candidates neck-and-neck among in the state (Clinton 42 percent, Sanders 40) and a Quinnipiac poll from earlier this week had Sanders leading over Clinton 49-44 percent).

Sanders appears to be sneaking up on Clinton nationally too. A new NYT/CBS poll this week showed Clinton with her smallest lead nationwide (Clinton 48 percent, Sanders 41).

So where is Sanders’ support coming from? Here’s a closer look at the numbers:

1. The Gender Gap: There is a huge gender gap among Sanders and Clinton supporters. Men overwhelmingly back Sanders (61 – 30 percent) according to the Quinnipiac University poll of Iowa voters out Tuesday. But the same poll finds that Clinton is fairing much better with women (55 – 39 percent).

2. The Liberals: Voters who consider themselves “very liberal” are overwhelmingly picking Sanders (57-41 percent), and those who consider themselves “somewhat liberal” are choosing him too, according to the Quinnipiac poll.

3. Education: Sanders is also the favorite among likely Iowa Democratic caucus participants without a college degree, the Quinnipiac polls finds. In this category, Sanders is leading Clinton by a substantial 10 percentage points (51-41 percent).

4. Trust on the Economy: Despite Clinton’s experience and name recognition, the same poll shows that Democratic participants think Sanders is better able than she is to handle the economy (51 -39 percent).

5. Favorability: Sanders continues to lead on the question of “favorability,” an issue that has been a sticking point for Clinton since the beginning of her campaign. However, among likely Democratic caucus participants, Clinton remains very favorable. The Quinnipiac poll showed Clinton with a 74- 21 percent favorable-unfavorable rating, and Sanders with an 87 – 3 percent favorability rating. The Des Moines Register poll released Thursday has these numbers event tighter: Clinton (86- 12 percent, favorable-unfavorable among) and Sanders (89-6 percent, favorable-unfavorable).