So long as the trough of government expenditure is large in both dollars and in non-monetary allocation of favor, money in politics will be important.
In government by the people and for the people where we have granted ourselves the right to petition the Government for redress of our grievances we will do so. When the various government agencies spend 35% of GDP and allocates many other prerogatives by administrative fiat - consider Bailouts, stimulus, special loans, too-big-to-fail, favors, mandates, barriers to entry, political appointments, tax breaks, campaign contributions, 'sole-source' procurement, connections, grants, government-union cooperation, exemptions, government sponsored enterprises, political insider trading, and legal bribery (this list from Intellectual Takeout, though many other examples are available), entrepreneurs will consider opportunities to make money via eating at the pig trough of government worth pursuit. Since the market doesn't directly allocate these opportunities to those that recognize them, spending money to influence those who do allocate them is the shortest path to capitalizing on these opportunities. Hence, money in politics.
All the money spent, all the effort and all the bureaucratic rules involved are not allocating our resources in an efficient way to the highest and best use of those resources which would create the most benefit for the people. Doesn't often feel like there isn't enough money to do the things we'd like to do as a country, like build roads or transit, or improve education or provide a safety net for the unfortunate? Miss allocate all the money and and we don't have any? What a surprise!
In order to reduce the amount of money and effort spent trying to influence those who allocate these opportunities in our present government by influence and reward peddlers we will need to reduce what they can control and give out. This means a move to smaller more local government and more government by principled law rather than administrative rule making in closed door or dimly transparent process.
Accurate Reality: To get rid of money in politics, shrink the goodies allocated by politicians.