President Trump is pouring hundreds of thousands of dollars into Facebook ads on the Supreme Court and conservative judges in the final stretch of his campaign, while Joe Biden is spending over a million on voter mobilization, according to an analysis by Axios using data from Bully Pulpit Interactive.

The big picture: Trump's Facebook ad messaging has fluctuated dramatically in conjunction with the news cycle throughout his campaign, while Biden's messaging has been much more consistent, focusing primarily on health care and the economy.

Why it matters: The Trump campaign's revolving door of targeted messaging shows the evolving dynamics of the race, and the campaign’s failure to hone in on one clear message.

• Instead, it's trying to juice turnout before Nov. 3 by throwing money at a series of issues that might rally Trump's base.
• The strategy is echoed in state-level spending. Several campaign officials have told Axios they don't have a clear sense of what strategy will secure 270 electoral votes.
• Trump campaign manager Bill Stepien has been dabbling in spending in Rust Belt battleground states in an effort to preserve multiple paths.

State of play: Last fall and winter, the majority of the Trump campaign's ads targeted the impeachment process and Special Counsel Robert Mueller.

• In the spring, it focused most of its ads on immigration and health care.
• In the early summer, it pivoted its ads to focus more heavily on "fake news" and targeting the media.
• In late August, around the convention, it began to spend heavily around criminal justice and on ads opposing defunding the police.

Biden's side has invested heavily in the past few months on voter mobilization and best voting practices during the pandemic.

Be smart: Facebook ads offer campaigns the unique ability to target potential voters narrowly and in real time. In total, the Trump campaign has spent over $142 million on Facebook ads this year, while the Biden campaign has spent over $89 million.

Flashback: Republicans struggled to deliver a clear, consistent message to voters during the midterm elections, leading to a blue wave in the House and Democratic gains in the Senate.

• Across all congressional races in 2018, health care was overwhelmingly the top issue Democrats referenced in their digital and TV advertising, per Ad Analytics. Republicans' messaging was all over the map.