L. A. Adamic and N. Glance, The political blogosphere and the 2004 us election: divided they blog, Proceedings of the 3rd international workshop on Link discovery, pp.36-43, 2005.

E. M. Airoldi, D. M. Blei, S. E. Fienberg, and E. P. Xing, Mixed membership stochastic blockmodels, Journal of Machine Learning Research, vol.9, issue.1, pp.1981-2014, 2008.

E. Bakshy, S. Messing, and L. A. Adamic, Exposure to ideologically diverse news and opinion on Facebook, Science, vol.50, issue.1, pp.3481130-1132, 2015.
DOI : 10.1037/0022-3514.50.1.163

N. Binkiewicz, J. Vogelstein, R. , and K. , Covariate-assisted spectral clustering, Biometrika, vol.17, issue.2, pp.361-377, 2017.
DOI : 10.1109/ICDM.2013.167

D. M. Blei, Probabilistic topic models, Communications of the ACM, vol.55, issue.4, pp.77-84, 2012.
DOI : 10.1145/2133806.2133826

D. M. Blei, A. Y. Ng, J. , and M. I. , Latent dirichlet allocation, Journal of machine Learning research, vol.3, pp.993-1022, 2003.

J. Chang and D. Blei, Relational topic models for document networks, Artificial Intelligence and Statistics, pp.81-88, 2009.

J. Chang and D. M. Blei, Hierarchical relational models for document networks. The Annals of Applied Statistics, pp.124-150, 2010.

M. Choy, M. L. Cheong, M. N. Laik, and K. P. Shung, A sentiment analysis of singapore presidential election 2011 using twitter data with census correction. arXiv preprint, 2011.

E. Colleoni, A. Rozza, and A. Arvidsson, Echo Chamber or Public Sphere? Predicting Political Orientation and Measuring Political Homophily in Twitter Using Big Data, Journal of Communication, vol.59, issue.3, pp.317-332, 2014.
DOI : 10.1145/1935826.1935863

N. B. Ellison, Social network sites: Definition, history, and scholarship, Journal of computer-mediated Communication, vol.13, issue.1 1, pp.210-230, 2007.

S. Gonzalez-bailon, A. Kaltenbrunner, and R. E. Banchs, The structure of political discussion networks: a model for the analysis of online deliberation, Journal of Information Technology, vol.11, issue.1, pp.230-243, 2010.
DOI : 10.1146/annurev.polisci.11.081306.070555

J. Grimmer and B. M. Stewart, Text as Data: The Promise and Pitfalls of Automatic Content Analysis Methods for Political Texts, Political Analysis, vol.103, issue.03, pp.267-297, 2013.
DOI : 10.1093/pan/mps035

S. Hebshi and O. Gara, The rohe of online social networking in the 2008 democratic presidential primary campains. preprint on webpage at http://www.shoshanahebshi.com/wp-content/uploads Social-Medias-role-in-primary-campaigns.pdf, 2011.

P. W. Holland, K. B. Laskey, and S. Leinhardt, Stochastic blockmodels: First steps, Social Networks, vol.5, issue.2, pp.109-137, 1983.
DOI : 10.1016/0378-8733(83)90021-7

T. Joachims, A probabilistic analysis of the rocchio algorithm with tfidf for text categorization-mellon univ pittsburgh pa dept of computer science, 1996.

A. M. Kaplan and M. Haenlein, Users of the world, unite! The challenges and opportunities of Social Media, Business Horizons, vol.53, issue.1, pp.59-68, 2010.
DOI : 10.1016/j.bushor.2009.09.003

B. Karrer and M. E. Newman, Stochastic blockmodels and community structure in networks, Physical Review E, vol.33, issue.1, pp.16107-16113, 2011.
DOI : 10.1088/1742-5468/2006/11/P11010

Y. M. Kim, Issue publics in the new information environment: Selectivity, domain specificity, and extremity, Communication Research, vol.36, issue.2 1, pp.254-284, 2009.

D. Kreiss and S. C. Mcgregor, Technology Firms Shape Political Communication: The Work of Microsoft, Facebook, Twitter, and Google With Campaigns During the 2016 U.S. Presidential Cycle, Political Communication, vol.13, issue.2, pp.1-23, 2017.
DOI : 10.1177/1461444814567985

M. J. Kushin and K. Kitchener, Getting political on social network sites: Exploring online political discourse on Facebook, First Monday, vol.14, issue.11, p.14, 2009.
DOI : 10.5210/fm.v14i11.2645

B. Pang and L. Lee, Opinion Mining and Sentiment Analysis, Foundations and Trends?? in Information Retrieval, vol.2, issue.1???2, pp.1-135, 2008.
DOI : 10.1561/1500000011

Z. Papacharissi, The virtual sphere the internet as a public sphere. New media & society, pp.9-27, 2002.

T. Qin and K. Rohe, Regularized spectral clustering under the degree-corrected stochastic blockmodel, Advances in Neural Information Processing Systems, pp.3120-3128, 2013.

H. R. Ramage, L. E. Connolly, and J. S. Cox, Comprehensive Functional Analysis of Mycobacterium tuberculosis Toxin-Antitoxin Systems: Implications for Pathogenesis, Stress Responses, and Evolution, PLoS Genetics, vol.75, issue.12, pp.1000767-1000768, 2009.
DOI : 10.1371/journal.pgen.1000767.s010
URL : https://doi.org/10.1371/journal.pgen.1000767

J. Ramos, Using tf-idf to determine word relevance in document queries, Proceedings of the first instructional conference on machine learning, pp.133-142, 2003.

S. P. Robertson, R. K. Vatrapu, and R. Medina, Off the wall political discourse: Facebook use in the 2008 us presidential election, Information Polity, vol.15, issue.1 2, pp.11-31, 2010.

K. Rohe, T. Qin, Y. , and B. , Co-clustering directed graphs to discover asymmetries and directional communities, Proceedings of the National Academy of Sciences, pp.12679-12684, 2016.
DOI : 10.1016/0378-8733(83)90021-7
URL : http://www.pnas.org/content/113/45/12679.full.pdf

G. Salton, A. Wong, Y. , and C. , A vector space model for automatic indexing, Communications of the ACM, vol.18, issue.11, pp.613-620, 1975.
DOI : 10.1145/361219.361220
URL : http://ecommons.cornell.edu/bitstream/1813/6057/1/74-218.pdf

J. Sivic and A. Zisserman, Video Google: a text retrieval approach to object matching in videos, Proceedings Ninth IEEE International Conference on Computer Vision, p.1470, 2003.
DOI : 10.1109/ICCV.2003.1238663
URL : http://www.cise.ufl.edu/class/cis6930fa07atc/Papers/Sivic03.pdf

S. Stieglitz and L. Dang-xuan, Political Communication and Influence through Microblogging--An Empirical Analysis of Sentiment in Twitter Messages and Retweet Behavior, 2012 45th Hawaii International Conference on System Sciences, pp.3500-3509, 2012.
DOI : 10.1109/HICSS.2012.476

S. Stieglitz and L. Dang-xuan, Social media and political communication: a social media analytics framework. Social Network Analysis and Mining, pp.1277-1291, 2013.
DOI : 10.1007/s13278-012-0079-3

A. Tumasjan, T. O. Sprenger, P. G. Sandner, and I. M. Welpe, Election Forecasts With Twitter, Social Science Computer Review, vol.30, issue.4, pp.402-418, 2011.
DOI : 10.1177/0261927X09351676

V. Luxburg and U. , A tutorial on spectral clustering, Statistics and Computing, vol.21, issue.1, pp.395-416, 2007.
DOI : 10.1017/CBO9780511810633

H. Wang, D. Can, A. Kazemzadeh, F. Bar, and S. Narayanan, A system for real-time twitter sentiment analysis of 2012 us presidential election cycle, Proceedings of the ACL 2012 System Demonstrations, pp.115-120, 2012.

S. Wattal, D. Schuff, M. Mandviwalla, W. , and C. B. , Web 2.0 and Politics: The 2008 U.S. Presidential Election and an E-Politics Research Agenda, MIS Quarterly, vol.34, issue.4, pp.669-688, 2010.
DOI : 10.2307/25750700

J. G. Webster, The marketplace of attention: How audiences take shape in a digital age, 2014.

B. Wellman, A. Q. Haase, J. Witte, and K. Hampton, Does the internet increase, decrease, or supplement social capital? social networks, participation, and community commitment, American behavioral scientist, issue.3 1, pp.45436-455, 2001.

C. B. Williams and G. J. Gulati, Explaining facebook support in the 2008 congressional election cycle, Working Papers, pp.26-27, 2009.

C. B. Williams and G. J. Gulati, Social networks in political campaigns: Facebook and the congressional elections of 2006 and 2008, New Media & Society, vol.5, issue.8, pp.52-71, 2006.
DOI : 10.1111/j.1460-2466.2005.tb02665.x

D. M. Witten, Classification and clustering of sequencing data using a Poisson model, The Annals of Applied Statistics, vol.5, issue.4, pp.2493-2518, 2011.
DOI : 10.1214/11-AOAS493

Y. Zhang and K. Rohe, WI 53706 USA E-mail: yilin.zhang@wisc.edu karlrohe@stat.wisc.edu Karolina Koc-Michalska, Marie Poux-Berthe Audencia Business School Communication and Culture Department 1 Rue Marivaux 44003 Nantes France E-mail: m.poux-berthe@live.fr kkocmichalska@audencia