Very much so. In-fact voting for someone is the most effective way to endorse (aka show approval and support of) a candidate outside of contributing $10,000 or more to their campaign.

endorse

[ en-dawrs ] Phonetic (Standard) IPA verb (used with object) , en·dorsed, en·dors·ing.

to approve, support, or sustain: 
to endorse a political candidate.

Synonyms: second, back, sustain, uphold, ratify, sanction
to designate oneself as payee of (a check) by signing, usually on the reverse side of the instrument.
to sign one's name on (a commercial document or other instrument).
to make over (a stated amount) to another as payee by one's endorsement.
to write (something) on the back of a document, paper, etc.:

to endorse instructions; to endorse one's signature.
to acknowledge (payment) by placing one's signature on a bill, draft, etc.

Vote

[ voht ] Phonetic (Standard) IPA noun

a formal expression of opinion or choice made by an individual or body of individuals, especially in an election.
the means by which such expression is made, as a ballot, ticket, or show of hands.
the right to such expression:

The 19th Amendment gave women the vote.
the total number of votes cast:

The heavy vote was a result of a new law that allows mailed-in ballots to be scanned days in advance of the close of voting.
the decision reached by voting, as by a majority of ballots cast:

The vote was in favor of the resolution.
a particular group of voters, or their collective expression of will as inferred from their votes:

Two large unions endorsed the candidate on Monday, as he continues to court the labor vote.
an informal expression of approval, agreement, or judgment:

My vote is for pepperoni—anchovies on pizza are gross!