President Trump is in a dead heat in Arizona in a head-to-head 2020 match-up with former Vice President Joe Biden, according to a poll by the left-leaning Public Policy Polling.

Forty-six percent of respondents to the survey said they would vote for Biden in the match-up and 46 percent said that they would vote for Trump. Eight percent of those surveyed said they were "not sure."

Biden finished best in a head-to-head match-up among the top four Democratic contenders.

Trump beat Sen. Bernie Sanders (I-Vt.) 47 percent to 46 percent; Sen. Elizabeth Warren (D-Mass.) 47 percent to 45 percent and former South Bend, Ind., Mayor Pete Buttigieg 47 percent 44 percent.

Arizona last voted for a Democrat in a presidential election in 1996 when former President Clinton won the state. It has voted for the Republican candidate in 16 of the last 17 presidential elections.

None-the-less, the state, which has 11 electoral college votes, is viewed as a battleground state as the population increases and demographics have changed. Sen. Kyrsten Sinema (D-Ariz.) took office in 2019, becoming the first Democratic senator from the state since 1995.

The poll comes as Democrats' electability has become a central theme in the primary.

A Gallup poll in November showed that a majority of those who identify as Democrats thought that a candidate who can beat Trump is more important than a candidate who shares the same values as them.

Biden has taken a moderate approach to the primary, targeting centrists and independents, while progressive heavyweights like Sanders and Warren have tried to appeal more to the Democratic base.

The Public Policy Polling survey also showed Sen. Martha McSally (R-Ariz.) trailing Mark Kelly, a former astronaut running as a Democrat for the Arizona Senate seat McSally filled following the death of Sen. John McCain (R-Ariz.).

The Arizona primary is scheduled for March 17.

The PPP poll was a survey of 760 Arizona voters conducted Jan. 2-4.