I don't think lobbying is a problem because the government has too much power, but rather because of the electoral system.

When voting is voluntary elections are won by the party that is best able to get out the vote. In order to get out the vote huge sums of money must be spent on political advertising and organization. When political parties are desperate for money it requires them to devote a lot of their time to fundraising and it makes them vulnerable to special interest groups with deep pockets (aka lobbyists). Voluntary voting means more opportunity for money to buy influence.

Compulsory voting, in contrast, means that almost all eligible voters will vote. Political parties can spend less money on advertising, less time fundraising, and more time developing policy and doing the job. Because the electors have to vote they're more likely to take an interest in the election, more likely to listen to the ideas being presented and vote accordingly. The only downside of compulsory voting is that there are more votes to count, but that cost is worth paying.

Compulsory voting is a practical step towards getting the money out of politics and improving the quality of a democracy.