The president arrived in Colorado this week. Udall did not appear with him. “It bothers me a lot,” one liberal Coloradantold a reporter, as she took her place at an Obama rally. Maybe Udall couldn’t believe that he was in a close race with Republican Cory Gardner, a cherub-faced congressman whose brightest moment in the spotlight came when he asked Kathleen Sebelius to defend the“brosurance” health care ad campaign. But Udall’s fear and trembling gave Gardner a week of easy attack lines. In campaigning, as in facing down a bear in the wilderness, it has never been a good idea to broadcast weakness.

So, how should other Democrats behave toward the president? This election year presents them with the most unforgiving Senate map a party has faced in a generation. There are seven seats currently held by Democrats in states won by Mitt Romney in 2012. Republicans only need to win six of those races (and hold on elsewhere) to take the Senate. There are at most two states, Georgia and Kentucky, where Democrats think they have any chance of winning a Republican seat. Romney carried those states too. When asked if she wanted President Obama to stump for her, Kentucky’s Democratic star Alison Lundergan Grimes nonanswered that hers was a “race that’s one about putting the people of this state first.”

Please remember that Mark Udall’s tap dance happened in a state that Barack Obama actually won. Twice! The 2014 election is likely to give us many more moments of gut-wrenching agony and Democrats going all Apostle Peter on the president they universally supported when elected in 2008. Members of the White House political team will grit their teeth and ask low-level campaign staffers if, you know, it would be OK for the commander-in-chief to show up. They will be told to call back in a few days. Often, they will be told, “No thanks, but send money.”

This won’t console the candidates, but they are not the first to find themselves trapped between their voters and an unpopular president. In 1998 and in 2006, both the second midterm years of struggling presidents, lots of candidates agonized over whether to let the most powerful man in the world land his plane near them. Their campaign staffers admit that there’s rarely a scheduling issue so serious as to cancel or skip a historic visit. They advise, mostly, to just let the guy come and campaign.

“There can be scheduling conflicts, but very few are real,” says Bob Shrum. In 1998, he was consulting for Senate candidate John Edwards in North Carolina, a state Bill Clinton had lost twice. “It was the middle of the impeachment stuff, it was a Southern state, and [incumbent Sen.] Lauch Faircloth was running with this predictable stuff—two ‘liberal lawyers,’ Clinton and Edwards.”

The Edwards campaign debated it—should Edwards raise money, in the state, with the soon-to-be-impeached president? They went for it, but they had an angle. Shrum approved ads that mocked Faircloth for his many (often procedural) votes supporting Clinton’s position. Like many Democratic campaigns of that year, Team Edwards went after the Republicans for their overzealous investigations of the president.

This worked, and Edwards won, but none of the incumbent 2014 Democrats are in as strong a position as Edwards was. Their predicament resembles that of Jim Talent, a one-term Republican senator from Missouri who faced re-election in the brutal 2006 cycle. George W. Bush had won Missouri twice, but his numbers had slipped into the rain gutter, and Talent went into the election trailing Democratic recruit Claire McCaskill. The White House called to see if President Bush could show up. The Talent campaign thought it over.

“The thinking was, everyone knows that Talent was a conservative,” remembers Talent’s campaign manager at the time Gregg Keller. “You’re not going to convince folks that the president is some persona non grata. It is what it is. We were looking at numbers and realized we needed a pop in southwest Missouri. The president did rallies in Joplin and Springfield—we had 10,000 people at both.”

The Talent campaign knew something that political scientists would have been happy to tell them. Presidential visits usually help a campaign, even when the president is wildly unpopular. Whether or not a president shows up to campaign, there is nothing stopping a rival from linking a candidate to the president of his party. He can Photoshop them together. The presidential appearance always serves to excite his base, as long as there is a base left to excite.

“I remember at one point being in the meeting where we’re finally making the decision,” says Keller of Bush’s proposed visit. “We have polling memos. We have the pro and con arguments. And I remember someone looking at me and saying, ‘You know what, if Bush comes into Springfield, and if our folks don’t get excited aboutthat, we were never gonna win anyway.’ ”

The visit went well, but the build-up was a little humiliating for the Bush White House. Other campaigns had flat-out refused presidential visits; other campaigns, they didn’t even bother to ask. This autumn will see countless fresh stories about how unpopular Obama is in most of the key states, paired with stories about how the candidates prefer visits by Hillary Clinton, or Bill Clinton, or Elizabeth Warren, or Joe Biden, or Howard Dean—basically, any Democrat who is not the president.