You could not be more misguided!
Campaign donations are, of course, a form of political speech and the 1st Amendment was written with such political speech in mind. Anonymity is essential to free political speech. Just ask anyone who donated to the Yes on 8 campaign in California. People have lost jobs because their donations supporting Prop. 8 were found out. Now the remaining donors are fighting in court to maintain their privacy.
And how many of the Founders would have hanged if King George had known who was writing what in the colonies? Many of the great works of the Revolution were published anonymously.
You cannot have free speech if there exists a simple means to punish it. The disclosure you and the Democrats call for would quell political speech in this country.
Is it better to have Soros, the Chinese, and the Saudi’s funneling hundreds of millions of dollars into US campaigns due to our lax disclosure rules? I very much doubt the Obama campaign was funded by small contributors as claimed.