#1. Legislative History
N. 1 The current provision of Art. 51 BV traces back to Art. 6 of the Federal Constitution of 1874, which in turn combined Art. 6 and 85 no. 7 of the Federal Constitution of 1848. The Federal Council Message on the Total Revision of the Federal Constitution of 20 November 1996 (BBl 1997 I 1) stated that the guarantee of cantonal constitutions represents a central element of the Swiss federal state. The provision secures cantonal constitutional autonomy on the one hand, while ensuring compliance with federal law on the other.
N. 2 During the 1999 total revision, a conscious decision was made not to specify the concept of "democratic constitution". The constitutional legislator did not want to impede the dynamic development of understanding of democracy through a rigid definition. The formulation "if they do not contradict federal law" replaced the earlier phrase "provided they contain nothing contrary to the provisions of the Federal Constitution" to clarify that the entire federal legal order serves as the standard (BBl 1997 I 252).
#2. Systematic Classification
N. 3 Art. 51 BV stands in the second title on Confederation, Cantons and Communes. The provision must be read in conjunction with the principles of federalism: → Art. 3 BV (cantons as sovereign within the framework of the Federal Constitution), → Art. 47 BV (preservation of cantonal independence), → Art. 49 BV (precedence of federal law) and → Art. 52 BV (constitutional order).
N. 4 The guarantee under Art. 51 para. 2 BV is concretised by → Art. 172 para. 2 BV, which empowers the Federal Assembly to grant the guarantee. The procedure is governed by → Art. 189 para. 1 lit. e BV for Federal Supreme Court review. The provision is closely related to political rights (→ Art. 34 BV) and equality before the law (→ Art. 8 BV).
#3. Elements of the Offence
N. 5 Cantonal constitution: The concept encompasses the formal constitution as the basic order of the canton. Some commentators define it as a collection of legally supreme norms that organise the political system, guarantee fundamental rights and establish state functions. The cantonal constitution must be formally distinguished from other cantonal enactments.
N. 6 Democratic constitution: The requirement of a democratic constitution requires, according to the Federal Council, at least an elected parliament and observance of the principle of separation of powers. The prevailing doctrine concretises this through four elements: periodic elections, universal and equal suffrage, majority principle and guaranteed opposition.
N. 7 Consent of the people: The mandatory constitutional referendum forms the core of democratic legitimacy. BGE 121 I 138 E. 5 also recognised the Landsgemeinde as a permissible form despite systemic weaknesses. Consent must be given in a free and fair procedure.
N. 8 Possibility of revision: The constitution must be revisable if the majority of those entitled to vote so demands. This encompasses both partial and total revisions. Blocking periods are, according to Kölz (Die Zulässigkeit von Sperrfristen für kantonale Volksinitiativen, ZBl 2001, 169), only permissible if they are proportionate.
N. 9 Contradiction with federal law: The cantonal constitution may not contradict not only the Federal Constitution, but the entire federal law. This includes federal acts, ordinances and international treaties (→ Art. 190 BV). BGE 130 I 1 E. 2 confirmed this comprehensive standard of review.
#4. Legal Consequences
N. 10 Guarantee: The guarantee by the Federal Assembly has constitutive effect. Without guarantee, a cantonal constitution cannot come into force. The guarantee is granted by federal decree and may be subject to conditions (Hotz, Probleme bei der eidgenössischen Gewährleistung kantonaler Verfassungen, ZBl 1982, 193).
N. 11 Federal Supreme Court review: The Federal Supreme Court may review guaranteed cantonal constitutional provisions in cases of application if federal law has developed since the guarantee was granted. BGE 140 I 394 E. 9 established this dynamic approach for electoral equality. However, the review only occurs in concrete cases of application, not abstractly.
N. 12 Hierarchy of norms: The cantonal constitution enjoys intra-cantonal precedence over acts and ordinances. BGE 143 I 272 E. 2.3 emphasised: «In the normative structure of the canton, the constitution then enjoys normative precedence.» This precedence must also be observed in cantonal legal application.
#5. Disputes
N. 13 Bicameral parliaments: The prevailing doctrine considers cantonal bicameral parliaments inadmissible as they contradict the principle of equality. Some commentators argue conversely that a bicameral system could indeed be democratic with factual reasons such as protection of linguistic minorities. Practice knows no cantonal bicameral parliaments.
N. 14 Qualified majorities: Another point of dispute concerns qualified majority requirements. The prevailing doctrine rejects these as undemocratic. Some commentators argue more differentially: qualified majorities should be permissible with factual justification, for instance to protect national minorities. The Federal Supreme Court has not yet decided this question.
N. 15 Majoritarian electoral systems: The admissibility of pure majoritarian electoral procedures for cantonal parliaments is disputed. Hangartner (Die Wahl kantonaler Parlamente nach dem Majorzsystem, ZBl 2005, 217) considers them contrary to federal law. BGE 145 I 259 E. 5 ultimately left the question open, but emphasised the strict requirements for constituency division in majoritarian systems.
#6. Practice Notes
N. 16 Constitutional revisions: For total revisions, contact should be sought early with the Federal Office of Justice. The informal preliminary examination can avoid later guarantee problems. Partial revisions also require guarantee, but the procedure is simplified (Bundi Caldelari/Rathgeb, ZGRG 2004, 92).
N. 17 Electoral reforms: Reforms of the cantonal electoral system must observe the developing Federal Supreme Court practice on electoral equality. BGE 143 I 92 E. 3 requires cross-constituency equality of success value in mixed systems. Pure majoritarian systems are subject to heightened requirements.
N. 18 Municipal organisation: The guarantee also covers provisions on municipal organisation. BGE 131 I 91 E. 3 accepted forced mergers but requires procedures under the rule of law. Municipal autonomy (→ Art. 50 BV) must be observed as a limitation.
N. 19 Dynamic guarantee: The guarantee once granted does not apply absolutely. In case of substantial changes to federal law or constitutional interpretation, adjustment may be necessary. BGE 139 I 195 E. 3 shows that constitutional provisions contrary to federal law may not be perpetuated.
N. 20 Procedural questions: Against the refusal of guarantee, recourse to the Federal Supreme Court is available (→ Art. 82 lit. b FSCA). The appeal is governed by → Art. 189 para. 1 lit. e BV. In the application of guaranteed norms, the Federal Supreme Court examines compatibility with higher-ranking law (Cereghetti, Die Überprüfung der Kantonsverfassungen, 1956, 45ff.).