There is no "Catholic vote". Catholics do not vote in bloc and never really have actually. But the "Catholic vote" has gone to the winner of the popular vote in every election since at least 1972 and possibly since 1932 since it just acts a microcosm of the country.
There are also no specific issues that appeal to Catholics, Catholic socons care about the same issues as evangelicals and other socons, affluent economic right Catholics care about their tax rate just like everyone else who fits the profile and liberal Catholics have the sane concerns as liberal Protestants and secular types. There is also no issues all of those groups agree on.
I would argue that at one time, they did. For many years preceding and just after JFK, Catholics identified pretty uniformly with the Democrats. This is because 1) sex issues were not big issues during that time 2) they identified with the Democrats on social justice and civil rights issues.
Whether you all like it or not, the Democrats have become a lot more secular, at least Democratic pundits (candidates can't really afford to do so in most areas). They demonize religion constantly because they see all religious people as evangelical southern fundamentalists, a profile which Catholics differ greatly from but are still targeted as thanks to liberals refusal to differentiate.