During a speech in New Hampshire, President Trump unveiled a new campaign line: "Whether you love me or hate me, you have got to vote for me."

Citing the strong economy, Trump told voters that if he loses, "your 401(k), everything is going to be down the tubes," so "you have no choice!" To underscore the point, when he finished speaking the music that came on was the Rolling Stones singing, "You can't always get what you want. But if you try sometimes, well, you might find, you get what you need."

Not far away, in Nashua, the Biden campaign rolled out the very same message about its candidate. "I know that not all of you are committed to my husband, and I respect that," Jill Biden told Democratic primary voters. "Your candidate might be better on, I don't know, health care, than Joe is. But you've got to look at who's going to win this election. And maybe you have to swallow a little bit and say, 'OK, I personally like so and so better,' but your bottom line has to be that we have to beat Trump."

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To put it another way: "Whether you love Joe or hate him, you have got to vote for him."

Trump and Biden are both running on the same message, but with one crucial difference: Trump is directing his at independent swing voters; Biden is directing that message at his base.

The New York Times reports that, despite his commanding lead in the polls, Biden faces a problem of low enthusiasm. While Sens. Elizabeth Warren, D-Mass., and Bernie Sanders, I-Vt., "have followings rooted in zealous support for their ideas," Biden's support is rooted in a belief that he is the candidate best positioned to beat Trump.

Patrick Murray, director of Monmouth University's Polling Institute, told the paper that while spending time recently in Iowa "I did not meet one Biden voter who was in any way, shape or form excited about voting for Biden. They feel that they have to vote for Joe Biden as the centrist candidate, to keep somebody from the left who they feel is unelectable from getting the nomination."

The danger of running on electability is that all it takes is one catastrophic gaffe or debate stumble for Biden's support to collapse. And even if Biden manages to secure the Democratic nomination, running a campaign built exclusively on ousting the sitting president, rather than enthusiasm for your own ideas, is not a winning strategy. Just ask President Mitt Romney.

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Trump, by contrast, has his base wrapped up and energized. The president consistently enjoys nearly 90 percent support among Republicans (in contrast with Barack Obama, who had just 75 percent support among Democrats at this stage in 2011, according to Gallup). For Trump, the risk of this strategy is not with his base, but with the swing voters who put him over the top in 2016.

In 2016, according to Axios, "20 percent of Trump's voters told exit pollsters they didn't like him." These reluctant Trump voters put Trump in the White House and are critical to his keeping it in 2020. Like many Americans, they are exhausted by the chaos of the Trump presidency. Biden is targeting his message directly at these voters, echoing George W. Bush's 2000 campaign pledge to restore "honor and dignity" to the Oval Office in the wake of the tumultuous Clinton presidency.

Yet, despite their exhaustion with Trump, many of these voters approve of his economic performance in office. Despite recent market turbulence, the U.S. economy remains strong. On Trump's watch, unemployment has reached a five-decade low, and our biggest economic problem is that we have 1.6 million more job openings than we have unemployed workers to fill them. And a decade after the Great Recession, wages are finally rising, with those at the bottom of the economic ladder benefiting the most.

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The problem is that Trump has made virtually no effort to win over these reluctant Trump voters again, much less expand his base by appealing to Americans who did not vote for him but are benefiting from his policies. He is betting that presidents seeking reelection in a full-employment economy don't tend to lose. The danger is that, if the economy takes a nosedive, his argument for reelection with these voters does as well.

Biden and Trump are giving voters an ultimatum rather than inspiration. They both may find that running on your unlikability is a risky strategy.

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