Why Obama and Romney can't talk about the future in specifics

After two presidential debates, the majority of people still don't know where either candidate would take the country and what their plan for the future is. Well, maybe not a majority of people, but most of the undecided people, at least. And the reasons both Obama and Romney each can't state their plan and their party's plan for the future of the country show why Congress is so hated right now.
For the president, all he has to do is tell America about each of the bills he has sitting in the House and say that getting those bills passed would be most of his agenda in his next administration. That these bill would drop the number of unemployed by at 1.5% (CBO's worst estimate), and with the savings in the defense department after the drawdown in Afghanistan going to pay down the debt and help domestic spending. But all that would take the help of the GOP, both in the House and the Senate. And since they have refused to pass these bills and have obstructed the president in the past, it's highly unlikely that they'd do so in the future. So America, not only vote for me, but make sure I have a Democratic Congress, and that is the future the country can have. But since President Obama knows that this would just cause the GOP to say, "See, we told you that he refuses to compromise", he doesn't go down that road. It doesn't matter that the GOP is actually the group that is blocking the president's agenda, but that would be their answer. And enough people would actually believe the GOP lie that it could cause Obama to lose. And why say something that may be construed to benefit the other side? So that's why Obama can't be specific when talking about the future.
But for Romney, he has another complete different problem. If he believes in the GOP 2012 plank, then in theory all he has to do is tell America what it is and allow the people to decide which way they want to take the country. But that's the rub. In polls, America has shown that they really don't like the GOP plank. Cutting out environmental policies to allow companies to pollute and making it harder to sue when they do, passing the Personhood Amendment, eliminating financial laws to allow banking institutions to go back to pre-2008 laws, passing the Blunt Amendment allow to businesses to opt out of any insurance plans if any part of the insurance includes something that the company finds morally unacceptable, get rid of the Department of Education, eliminating all grants and loans to college students,  and overturn the Lily Ledbetter Act and the Consumer Protection Agency bill. These are all in the plank in some form, and all would be widely unpopular with the American people. Even the Affordable Healthcare Bill (Obamacare), which the GOP wants to repeal, while being slightly unpopular (It's now 47 for 53 against), isn't really all that unpopular. Take out the individual mandate, and all the other parts of the bill are acceptable to the American people. This is why Romney can't get specific.
But one thing Romney doesn't need talk about is Democratic obstruction. For in the House, the GOP is in control. And the GOP may get control hold the Senate. This would allow the GOP plank to go through pretty much unobstructed. But even if the GOP gains control of the Senate, can't the Democrats filibuster just like the GOP has done? Well, while the minority party in the Senate can filibuster just about bill, they can't filibuster an appropriations bill. And all they need to do is to de-fund all the agency they can't get rid of, and the effect is the same. So while one party can do what they want only if the other party agrees, the other party doesn't need that to happen. Think this would be acceptable to most Americans if this was explained to them? This is why the American people need both candidates to tell the truth about the future, and another reason why Romney will never get specific about the future.