The Republican Definition of Democracy is not Inclusive
The Republican Party knows that it will not get any votes from the left and even many independents. Thus it is their strategy to win elections by keeping as many of those voters on the sidelines as they can. They do this in two ways: first, by framing the "other guy" as not being worthy of the vote or portraying them in a way that causes voters in that base to give up. Since most liberals would not vote for a Republican under any circumstance, keeping a liberal vote on the sideline is still a vote for them. The other way, of course, is preventing voters from even being eligible to vote. Their main tool are these ludicrous voter ID laws that are passed on the wholly unfounded premise that voter fraud exists, and also their efforts to stymie voter registration. How can you support a party that wants to make our country less of a democracy?