A presidential appearance ties the candidate to unpopular Washington, Dowd said, when candidates may be trying to show their independence.
In the latest ABC News/Washington Post poll, 71 percent of Americans said they disapprove of Congress -- the most unpopular it has been since the Republican swept into power in the landslide of 1994.
Given that dismal view of the legislative branch, it is no wonder that candidates are trying to separate themselves from Washington when they are on the trail back home. But can they do that and stand beside the president?
"Barack Obama is no longer the outsider, he is Washington, he is the president and leader of the entire government now held by Democrats," Dowd said. "So he shows up and basically says I'm here from Washington and I'm here to help when most voters have no desire to hear that."
After Brown's stunning victory in Massachusetts, Obama sought to rally Democratic senators and urged them to keep their eye on the ball.
In a question-and-answer session earlier this month, the president told Democratic senators to avoid playing it safe in order to win in November. Obama said that right now the best strategy for Democrats is to get things done.
"All that's changed in the last two weeks is that our party's gone from having the largest Senate majority in a generation to the second-largest Senate majority in a generation. And we've got to remember that," the president said. "We still have to lead."
The question-and-answer session itself was an element of the party's political strategy. Seven of the eight senators who got to ask a question of Obama in front of television cameras are facing tough re-election battles this fall.
The session provided nice sound bites for their constituents back home, showing the senators challenging the president and focusing on issues of local importance.
The political roadmap for Obama over the next nine months is far from certain, but he has said himself that he wants to hit the road more than he did in 2009. That increased travel allows him to tack on political events to his official schedule and bring media coverage and attention to a Democratic candidate through the use of the presidential bully pulpit and all the fanfare and trappings of the presidency like Air Force One and limo rides.
While White House and party officials say there is a large stack of requests for the president's time, Dowd sees an interesting dynamic developing over the next few months as candidates shy away from a presidential visit.
"Candidates will start saying, 'We'd love your money but we really don't want you hanging around,'" Dowd said. "I think you're going to see more and more of that and see more quote-unquote 'scheduling conflicts.'"
ABC News' Jonathan Karl contributed to this report.