Because those people who win represent your city, state, country, etc. The president doesn't pass laws. The congress does. Even if he veto's them the congress cans till vote for that law. Every vote matters and counts.
● Congressional Elections and Midterm Elections. Congressional elections affect your state's representation in Congress.
●Congress is the legislative branch of the federal government that includes the House of Representatives and the Senate. ____________________________________________________________________________________
Answer: Checks and balances. They want to keep each branch in check. Legislative branch makes the laws, and the executive branch gives the president the ability to veto it, keeping the balance.