By Anthony Salvanto, Fred Backus, Jennifer De Pinto, Sarah Dutton

Donald Trump holds the lead heading into the final days before the Michigan primary, looking to extend his overall delegate lead after a string of Super Tuesday wins. Trump is at 39 percent, Ted Cruz is in second place at 24 percent and Marco Rubio and John Kasich neck-and-neck for third at 16 percent and 15 percent respectively.

The poll provides a look at why the so-called establishment voices attempting to slow Trump's momentum haven't succeeded, at least not so far. By four to one, Michigan Republicans say they're less likely to vote for a candidate with establishment backing, not more so.

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Among those not backing Trump, there is no consensus on what the party should do if Trump keeps winning. Forty-three percent would prefer the party do all it can to keep Trump from the nomination, but 37 percent feel the party should rally behind Trump and look to win with him in November.

But Trump is overwhelmingly seen as the candidate who'd favor "regular people" over big donors -- seven in ten say so -- while the other candidates get more mixed views on this measure.

Trump holds leads over other candidates on ability to win in November, to bring change, and "get things done," but also the candidate whose campaign is most focused on personal attacks. Trump and Kasich are virtually tied on which candidate best understands the middle class. Meanwhile, one-third of voters feel Cruz is too conservative, and four in ten feel Trump is not conservative enough.

Kasich is the candidate most seen as honest and trustworthy (74 percent say so), while the other candidates are more mixed in this regard. Trump is at 48 percent and Cruz at 53 percent. Self-reported views of Kasich are also on the rise, as by more than two to one voters say their view of him is improving of late.

On the Democratic side, Hillary Clinton holds a comfortable double-digit lead over Bernie Sanders, helped -- as in many Super Tuesday states last week -- by strong support from African American voters.

Clinton's path to a Michigan lead in the poll looks much the same as her path in previous states: she leads on being seen as qualified and on being commander-in-chief, but Sanders is seen by more as honest. He is also seen by more as principled, and better on fixing income inequality.

The CBS News 2016 Battleground Tracker is a panel study based on 1,415 interviews conducted on the internet of registered voters in Michigan. The poll was conducted by YouGov, an online polling organization. Full methodology can be found below and at this link.