Trump gets a warning from Republican voters in Pennsylvania as more than 155,000 vote for Nikki Haley in the primary... even though she dropped out last month

Nearly 17 percent of Republican voters in Pennsylvania cast their ballots on Tuesday for former U.N. Amb. Nikki Haley – even though she is no longer in the presidential primary race.

The vote was largely a protest against Donald Trump and some worry that Haley's ability to continue to win over primary voters is a sign the former president is a weaker general election candidate than polls suggest.

Although Trump already clinched his third straight Republican nomination last month, Haley, who suspended her campaign in early March, still earned 156,539 votes as of Wednesday morning with just 5 percent left to count.

Trump still dominated the state with 82.8 percent of the vote in the inconsequential primary and every single county in the state voting for the former president.

More than 155,000 Republicans in Pennsylvania cast their ballots for Nikki Haley in Tuesday's presidential primary – even though she dropped out of the race last month

Pennsylvania is a state highly important to the 2024 general election and could ultimately decide the results in November.

President Joe Biden won the swing state in 2020 by 80,500 votes but Trump won Pennsylvania against Hillary Clinton in 2016 by 68,000 votes.

The Keystone State has a closed primary, meaning only those registered with a specific party can participate in that primary election in Pennsylvania.

And even though voters in Pennsylvania knew Haley could not win and was no longer an official candidate, 16.4 percent of Republicans felt it was still worth it to cast their ballot in a sign of voting against Trump earning another White House term.

Zombie voting is not a new phenomenon and is a way for voters to still cast their ballots for preferred candidates – or to protest other candidates still in the running. And Haley's continued sizable minority voting bloc proves effective as a way for anti-Trump Republicans to make their voice heard at the primary ballot box.

Trump and Biden have already earned the number of delegates needed to clinch their respective parties' presidential nominations in 2024 – meaning the 2020 rematch that most voters said they didn't want is chugging ahead.

Some warn that the sizable minority of voters still willing to case their ballot against Trump and for Haley is a big warning that the former president is not as a strong of a general election candidate as previously thought

Also in Pennsylvania on Tuesday, Biden decisively won his primary with 88.2 percent of the Democratic vote. But Rep. Dean Phillips (D-Minn.) earned 6.5 percent in the state from those Democrats who don't want to see Biden earn a second term.

Phillips was one of the only legitimate challengers to Biden and he dropped out of the primary race in early March. 

There are still 10 more states left to hold both their Democratic and Republican primaries before the conventions this summer, where the parties will officially nominate their candidates. But no results will have consequences for the November election.