Bernie Sanders (Andrew Harnik/AP)

New polling out over the past 24 hours suggests that Bernie Sanders is in a dead heat with Hillary Clinton in Iowa. Those results come as Clinton is upping her attacks on Sanders over his past votes on gun control measures, and Sanders appears to be getting more aggressive about Bill Clinton and his role in his wife's campaign.  Oh, by the way, the Iowa caucuses are also only 21 DAYS AWAY! With so much going on in the Democratic primary, I reached out to Tad Devine, chief strategist for Sanders's campaign, to get his take on the state of the race — and how his candidate can win. Our conversation, conducted via email and edited only for grammar and flow, is below.

FIX: NBC/Marist released a poll Sunday that showed Bernie within the margin of error in Iowa. Does that jibe with what you guys are seeing? And if so, what explains the momentum there?

Devine: We believe the race has tightened in recent weeks in Iowa. I think a number of factors have led to the tightening. First, Bernie's message is very powerful: America has a rigged economy that is sending most of the new wealth to the top, and it's being held in place by a corrupt system of campaign finance. The Clinton campaign went on TV in Iowa (and New Hampshire) on Aug. 4. We started our media campaign Nov. 4. I think we have made up a lot of ground in both places since then.

Also, Bernie is a very strong messenger for that message. He is credible and authentic, and people understand that these fights against powerful interests are the work of his life.

FIX: Hillary is going hard at Bernie on guns. How do you guys respond? How vulnerable is your candidate on his past voting record on guns? And what does it tell you about the state of the race that she is attacking Sanders as aggressively as she is?

Devine:  When I saw Secretary Clinton call into "Hardball" on Friday night, I knew they must be very concerned about what was happening in the early states and elsewhere.

Bernie Sanders earned his D- lifetime rating from the NRA, as well as his most recent rating of "F." He has supported a ban on assault weapons since the late '80s, when he lost his first race for the House of Representatives based on his pledge to ban those weapons. He has supported background checks as well, and supports a law preventing straw purchases of guns.

Bernie supports President Obama's executive actions on guns, and the president's efforts to take on the gun lobby. The truth is, while there are past differences on some gun legislation, going forward there are not big differences on this issue. That is why I don't think the gun issue will change the outcome of the race.

FIX: Bernie has long pledged not to attack Clinton (or the Clintons) on personal matters. But at a town hall in Iowa late last week, he said that what Bill Clinton did was "totally, totally, totally disgraceful and unacceptable.” Isn’t that a violation of his no-attack principle? If not, why not?

Devine: I think if people saw the question he was asked at that town hall meeting and the context, they would not view that part of one sentence you cited as a "negative attack." He was asked a question and gave an answer which, in part, is not dissimilar to what almost all Democrats were saying at the time of President Clinton's impeachment trial — that what the president did was wrong.

Bernie also stated that he was running against Hillary Clinton, not Bill Clinton, and has made clear repeatedly that he is not interested in making President Clinton's past an issue in the campaign. Bernie wants to talk about the issues that affect the lives of people today in America.

FIX: Let’s say Hillary wins Iowa. Bernie wins New Hampshire. What do you say to critics who insist that Sanders has no wins beyond Feb. 9 on the calendar? Where can he win next? And how, given how much he has struggled to win over black and Hispanic voters from Clinton?

Devine: Fix readers may remember Walter Mondale's campaign against Gary Hart when Senator Hart won the New Hampshire primary. I do because I was counting delegates for Mondale.

The momentum that comes from an early victory is huge, and I believe that Bernie's campaign is in position to take advantage of that momentum. We have strong campaigns on the ground in Nevada and South Carolina, and we have been on radio in Nevada since November and on TV in Nevada since late December. (The Clinton campaign joined us on TV in Nevada on Friday).

We have also been on radio in South Carolina since November. So I think we can compete and win in a number of states, like Massachusetts, Colorado, Minnesota and Vermont on March 1st and elsewhere as we move into big battlegrounds like Michigan, Illinois and Ohio.

As to support from Latinos and African Americans, I think that support is growing by the day. For example, in the most recent Field poll in California, Bernie's support with Latinos grew from 3.2 percent in May to 35.3 percent in the poll they released last week. And that all occurred in a state where we have had no paid media. I think it bodes well for our potential to win substantial support from Latinos, African Americans and others as they come to know more about Bernie and his plans for their future.

FIX: Finish this sentence: Bernie Sanders is a better general election candidate than Hillary Clinton for Democrats because ____________. Now explain.

Devine: He can build a broad-based coalition that will elect Democrats up and down the ballot.

Bernie, alone among Democrats, can build the kind of coalition that Barack Obama built in 2008. It begins with young people who are supporting him as they did Obama. And it continues with independents. Gallup today released its latest survey with the headline "Democratic, Republican identification near historical lows." Independents, for the fifth consecutive year in the Gallup survey, comprise over 40 percent of the American electorate.

We are already seeing general election polling that recognizes Bernie as by far the strongest candidate for the Democrats [because of] his core strength with independents. The truth is if we do not have a nominee who can win support from independents and even some Republicans, we will lose. Bernie won 25 percent of the Republican vote in his last reelection to the Senate (with 71 percent of the total vote).

Also, so many people who now feel left out and left behind will, we believe, be motivated to participate in the process because Bernie alone speaks with conviction and authority to the concerns that are at the center of their lives.