Washington DC - President Joe Biden is attempting to take votes away from his challenger, Donald Trump, by targeting Nikki Haley supporters in Pennsylvania.

According to CNN, Biden's campaign spent "mid-six figures" on the ad buy, which is currently running on social media sites and streaming platforms such as YouTube and Hulu.

The 30-second ad, titled "If you voted for Nikki Haley...", features a montage of Trump publicly insulting Haley throughout the Republican primaries and dismissing the idea of winning over her support.

The strategy was inspired by the recent primary election in Pennsylvania, where Haley, who dropped out of the race last month, received 16% of the vote.

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As Haley was not even on the ballot, critics believe the vote was a protest against Trump, prompting the Biden campaign to take advantage of the apparent opportunity.

"Our campaign has been clear from the beginning that we welcome anyone who knows that four more years of Trump would destroy our freedoms and devastate our country," campaign communications director Michael Tyler told NBC10.

Biden also faced a wave of protest votes during the recent primary, with over 5% choosing the "write-in" option, largely in opposition to his continued support for Israel as they continue their bombing campaign in Gaza.