This idea just popped into my mind the other day and I couldn't get it out again. I'm normally a Josh and Donna kind of girl but I couldn't get this out of my head. There will be elements of both Josh/Donna and Sam/Donna later in the story.

It takes place about 7 years after Bartlet leaves office and the rest will explain itself later in the story.

Disclaimer: I don't own any of this, just borrowing

Donnatella Moss sat alone in her large D.C. apartment drinking wine, eating Chinese takeout and reading the New York Times. She had turned off her cell phone and even taken drastic measures and unplugged her house phone from the wall. Her busy schedule as Congresswoman from Wisconsin afforded her little private time so she had stolen a little this evening. So Donna was slightly miffed when her buzzer rang announcing a guest. Donna flung open her door, ready to reprimand whoever was on the other side only to be pleasantly surprised.
"Sam Seaborn!" she exclaimed happily pulling him into her apartment and into a hug.
"How did you get in?" she questioned cheekily as she pulled away.
"Well when your doorman exclaimed 'Mr. Seaborn, I'll be voting you for President in November' I was pretty sure I wouldn't have to ask permission to come in." Sam explained smiling down at Donna.
"You've been in town for a few days. Why didn't you call?" she questioned and then continued without waiting for an answer. "You know I still can't believe it. It feels like yesterday that you were Bartlet's speech writer and Haffley was Speaker of the House and now you're running against each other for president." Donna finished as she pulled Sam into her living room and seated herself next to him on the couch, Chinese food all but forgotten. Donna and Sam had kept in touch over the years as her was now a Senator and she was a Representative and she was thrilled to see him, all thoughts of a solitary night leaving.
"You look fantastic." Sam told her, smiling.
"Not so bad yourself, Mr. Democratic Candidate for President." Donna teased.
"Why thank you, Congresswoman." Sam answered playfully before suddenly turning serious
"So I guess I should get to the reason I'm here." Sam announced, his good humor turning to a more staid expression. Donna nodded encouragingly so Sam continued.
"This might be the craziest thing I've done in a very long time, but Donntella Moss, will you marry me?" Sam questioned smoothly sliding off of the couch onto one knee in front of Donna.
"What?!" Donna yelped, shooting off the couch so quickly that she almost knocked Sam over.
"No, think about it for a moment, I promise it makes sense." Sam cajoled as he stood to face her.
"It won't make sense until I've had about another bottle of this." Donna said pointing to the wine at her table and crossed to get her glass. She offered Sam some but he shook his head no. She walked back over to the couch and reseated herself.
"OK, explain." She ordered.
"So I'm single and your single and..." he started.
"Ding ding ding wrong answer." She cut him off. "Try again."
"So Toby had this idea."
"Getting warmer." Donna interrupted.
"So besides being the youngest presidential candidate in quite a while I'm also very unmarried which Toby seems to think will really hurt my chances, since Haffley is quite happily married. And polls seem to indicate that a young, beautiful, political wife such as yourself would even the odds astronomically." Sam paused slightly gauging Donna reaction. She was starting to relax and had even put her wine glass back down, both of which Sam considered good signs.
"You've done polls?" she questioned and Sam nodded.
"So this isn't a joke. You're serious? And you've even talked to Toby?"
"Toby, and CJ. They both think its insane but might be just what we need. And I even brought it up with Josh." Sam watched Donna tense slightly as he delivered this last bit of news. He knew that her relationship with Josh had been uncomfortable at best over the last few years but she recovered quickly.
"So what did the potential VP say?" she asked in a tone that might be interpreted as teasing but Sam detected the venom beneath her words.
"There was some yelling cursing and I think he yelled 'over my dead body' at least three times, but he's stopped throwing things at me when I enter the room. So that's a good sign." Sam smiled at Donna but when she didn't return it he decided that now was as good of a time as any to drop another bomb.
"He and Amy are separated. They'd have already divorced except for the kids." Sam tensed waiting for her response.
"What I am supposed to say Sam? They can stay married or move to two separate countries for all I care." Donna responded in a weary tone that suggested that she did care.
"So you think you could become president with me as your wife but not without me?" Donna asked steering the conversation back to their previous topic.
"We would be the perfect couple Donna. Or at least appear to be. But I beginning to think this is insanity and we should forget about it." Sam said softly. Donna took a deep breath and her last gulp of wine and reached her hand out to Sam.
"No, lets do it." Donna answered searching his face with her eyes.
"I've given up on love and at least this way I can help your career." she finished.
"Well that's not the most romantic way to accept, but this isn't the most romantic proposal ever either." Sam smiled. "You mean it?" he questioned. Donna smiled impishly and squeezed his hand.
"This is just so crazy it might be genius. I mean it will be a sham but a brillient one. We only have to pretend to be the perfect couple, right?" She answered.
"Exactly. But we have a lot to do. Tell our parents, make announcements, and plan a wedding. Not to mention all of the campaigning." Donna simply looked overwhelmed so Sam continued.
"I think we have to have a big wedding. If we were really getting married we'd want it big, right? I mean neither of us has ever been married so sneaking off to the justice of the peace would look funny."
"Everything is about the pubic eye now isn't it? If this is going to work we have to charm the public and appear completely in love." Donna answered.
"Will you meet me for lunch tomorrow? We can go buy a ring." He smiled lopsidedly.
"We should go visit my parents this weekend." Donna stated.
"Exactly what I was thinking." Sam responded.
"If we can convince them we might have a shot." Donna said pragmatically.
"There's something we need to do before lunch tomorrow." Sam suggested tentatively.
"If we don't go tell Josh we might have to find a new VP after his head spins around and explodes." Sam tried to soften the situation with humor and Donna smiled slightly.
"I'd better do it alone." She responded determinedly. When Sam tried to disagree with her she held up her hand and silenced him.
"If I go alone, there will be yelling but no flying objects." She smiled slightly.
"You're sure?" Sam asked.
"I'm not a love stuck twenty something anymore. I can do it." Donna replied assuredly.
"So how does two months sound for the wedding? And two weeks for the engagement party?" Sam asked.
"Is that enough time?" queried Donna.
"It will have to be." Sam answered. "I'll call you tomorrow and we can decide on a place to eat. Somewhere noticeable where we can show off our newfound love and enormous wedding ring." Sam said as he got to his feet. Donna stood with him and he moved in to kiss her on the cheek but at the last moment changed his mind. If they were going to pull this off kissing would be the least of their worries. He leaned in and kissed her softly and chastely on the mouth.
"Good night, crazy man." Donna smiled at him.
"Good night the future Mrs. Sam Seaborn." He answered rakishly.
With one last smile Donna closed the door on Sam and threw herself onto her couch. If you had told her two hours ago that she would agree to marry of all people Sam Seaborn she would have laughed, she thought to herself. And Donna lay on the couch in a slightly wine induced stupor until she finally drifted off to sleep.