Butwithoutaconstitutionallimitonitsduration，itmustbeconceded，thatapowerinthelegislaturetoprotractitsowncontinuance，wouldbedangerous。BlackstoneattributesthemisfortunesofCharlesI。tohishavingunadvisedlypassedanacttocontinuetheparliament，theninbeing，tillsuchtimeasitshouldpleasetodissolveitself，andthisisoneofthemanyproofsthatthemuchpraisedconstitutionofthatcountrywantsthecharacterofcertainty。NoactofcongresscouldprolongthecontinuanceofthelegislaturebeyondthetermfixedbytheConstitution。
WilliamRawle:AViewoftheConstitution:ChapterIIICHAPTERIII。OFTHESENATE。THEsenate，onaccountofitsmorepermanentdurationandvariousfunctions，willreceiveourfirstattention。
IftheinfusionofanyaristocraticqualitycanbefoundinourConstitution，itmustbeinthesenate；butitissojustlytemperedandregulatedbyotherdivisionsofpower，thatitexcitesnouneasiness。Themoundsandsafeguardswithwhichitissurroundedmustbeviolentlybrokendown，beforeanypoliticalinjurycanarisefromthesenate。
Thesenatorsareappointedfromtimetotime，bythelegislaturesofthedifferentstates；butifavacancyhappensduringtherecessofthestatelegislature，theexecutivethereofmaymaketemporaryappointmentsuntilthenextmeetingofthelegislature，whichshallthenfillsuchvacancies。
Thevestingthispowerinthestatelegislaturesistheonlymaterialremnantofthefederativecharacterofthelatecongress；butthedelegatesthenappointedpossessedthewholepower；thosenowappointed，holdbutapartofthepowersofthegeneralgovernment。Itisrecommendedbythedoubleadvantageoffavouringaselectappointment，andofgivingtothestategovernments，suchanagencyintheformationofthegeneralgovernmentaspreservestheauthorityoftheformer，andcontributestorenderthemlivingmembersofthegreatbody。1Whethertheappointmentshallbemadebyajointoraconcurrentvoteofthetwobranches，whenthelegislatureofastateconsistsoftwobranches，asitnowuniversallydoes，theConstitutiondoesnotdirect。Thedifferenceis，thatinajointvote，themembersofbothhousesassembletogetherandvotenumerically。Aconcurrentvoteistakenbyeachhousevotingseparately，andthevoteofonereceivingtheassentoftheotherbranch。