Unemployment rates edged up year over year in Mississippi, Arizona, North Carolina, Indiana, South Carolina, Kansas, Missouri and Nebraska, according to the latest numbers from the Bureau of Labor Statistics.

But in a handful of key states he carried in 2016, unemployment numbers are not moving in his favor, which could spell trouble in 2020, according to new employment numbers out Friday.

The economy is perennially a key issue for American voters in elections, and President Donald Trump is counting in part on tail winds from a strong economy to carry him to victory.

Trump's net approval rating remains high in most of these states. But more people in Arizona and North Carolina disapprove of his job as president than approve, according to the latest Morning Consult poll.

North Carolina has 15 electoral votes and Arizona has 11. Moreover, Trump pulled off somewhat narrow victories over Hillary Clinton in each state in the 2016 election -- 3.6% in North Carolina and 3.5% in Arizona.

In Indiana, Nebraska and Kansas, Trump's net approval ratings are in the low single digits, according to the Morning Consult poll. The states have a combined 22 electoral votes. Trump won by more comfortable margins in these states -- 19% in Indiana, 25% in Nebraska and 20.5% in Kansas.

It is unlikely that all eight states, which have a combined 73 electoral votes, would flip to the Democratic candidate in 2020.

Trump lost the popular vote in 2016, but won in the Electoral College thanks in large part to victories in Pennsylvania, Ohio and Michigan, which all voted for Democrat Barack Obama twice. Employment edged up year over year in all three states.